diff --git a/chrome/browser/extensions/back_forward_cache_browsertest.cc b/chrome/browser/extensions/back_forward_cache_browsertest.cc
new file mode 100644
index 00000000000000..1a3d826d0ad74e
--- /dev/null
+++ b/chrome/browser/extensions/back_forward_cache_browsertest.cc
@@ -0,0 +1,137 @@
+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/extensions/extension_browsertest.h"
+#include "chrome/test/base/ui_test_utils.h"
+#include "content/public/common/content_features.h"
+#include "content/public/test/browser_test.h"
+#include "extensions/common/extension.h"
+#include "net/dns/mock_host_resolver.h"
+
+namespace extensions {
+
+class ExtensionBackForwardCacheBrowserTest : public ExtensionBrowserTest {
+ public:
+  explicit ExtensionBackForwardCacheBrowserTest(
+      bool allow_content_scripts = true) {
+    feature_list_.InitWithFeaturesAndParameters(
+        {{features::kBackForwardCache,
+          {{"content_injection_supported",
+            allow_content_scripts ? "true" : "false"}}}},
+        {features::kBackForwardCacheMemoryControls});
+  }
+
+  void SetUpOnMainThread() override {
+    host_resolver()->AddRule("*", "127.0.0.1");
+    ExtensionBrowserTest::SetUpOnMainThread();
+  }
+
+ private:
+  base::test::ScopedFeatureList feature_list_;
+};
+
+class ExtensionBackForwardCacheContentScriptDisabledBrowserTest
+    : public ExtensionBackForwardCacheBrowserTest {
+ public:
+  ExtensionBackForwardCacheContentScriptDisabledBrowserTest()
+      : ExtensionBackForwardCacheBrowserTest(/*allow_content_scripts=*/false) {}
+};
+
+IN_PROC_BROWSER_TEST_F(
+    ExtensionBackForwardCacheContentScriptDisabledBrowserTest,
+    ScriptDisallowed) {
+  ASSERT_TRUE(LoadExtension(test_data_dir_.AppendASCII("back_forward_cache")
+                                .AppendASCII("content_script")));
+
+  ASSERT_TRUE(embedded_test_server()->Start());
+  GURL url_a(embedded_test_server()->GetURL("a.com", "/title1.html"));
+  GURL url_b(embedded_test_server()->GetURL("b.com", "/title1.html"));
+
+  // 1) Navigate to A.
+  content::RenderFrameHost* rfh_a =
+      ui_test_utils::NavigateToURL(browser(), url_a);
+  content::RenderFrameDeletedObserver delete_observer_rfh_a(rfh_a);
+
+  // 2) Navigate to B.
+  content::RenderFrameHost* rfh_b =
+      ui_test_utils::NavigateToURL(browser(), url_b);
+  content::RenderFrameDeletedObserver delete_observer_rfh_b(rfh_b);
+
+  // Expect that |rfh_a| is destroyed as it wouldn't be placed in the cache.
+  EXPECT_TRUE(delete_observer_rfh_a.deleted());
+}
+
+IN_PROC_BROWSER_TEST_F(ExtensionBackForwardCacheBrowserTest, ScriptAllowed) {
+  ASSERT_TRUE(LoadExtension(test_data_dir_.AppendASCII("back_forward_cache")
+                                .AppendASCII("content_script")));
+
+  ASSERT_TRUE(embedded_test_server()->Start());
+  GURL url_a(embedded_test_server()->GetURL("a.com", "/title1.html"));
+  GURL url_b(embedded_test_server()->GetURL("b.com", "/title1.html"));
+
+  // 1) Navigate to A.
+  content::RenderFrameHost* rfh_a =
+      ui_test_utils::NavigateToURL(browser(), url_a);
+  content::RenderFrameDeletedObserver delete_observer_rfh_a(rfh_a);
+
+  // 2) Navigate to B.
+  content::RenderFrameHost* rfh_b =
+      ui_test_utils::NavigateToURL(browser(), url_b);
+  content::RenderFrameDeletedObserver delete_observer_rfh_b(rfh_b);
+
+  // Ensure that |rfh_a| is in the cache.
+  EXPECT_FALSE(delete_observer_rfh_a.deleted());
+  EXPECT_NE(rfh_a, rfh_b);
+  EXPECT_TRUE(rfh_a->IsInBackForwardCache());
+}
+
+IN_PROC_BROWSER_TEST_F(
+    ExtensionBackForwardCacheContentScriptDisabledBrowserTest,
+    CSSDisallowed) {
+  ASSERT_TRUE(LoadExtension(test_data_dir_.AppendASCII("back_forward_cache")
+                                .AppendASCII("content_css")));
+
+  ASSERT_TRUE(embedded_test_server()->Start());
+  GURL url_a(embedded_test_server()->GetURL("a.com", "/title1.html"));
+  GURL url_b(embedded_test_server()->GetURL("b.com", "/title1.html"));
+
+  // 1) Navigate to A.
+  content::RenderFrameHost* rfh_a =
+      ui_test_utils::NavigateToURL(browser(), url_a);
+  content::RenderFrameDeletedObserver delete_observer_rfh_a(rfh_a);
+
+  // 2) Navigate to B.
+  content::RenderFrameHost* rfh_b =
+      ui_test_utils::NavigateToURL(browser(), url_b);
+  content::RenderFrameDeletedObserver delete_observer_rfh_b(rfh_b);
+
+  // Expect that |rfh_a| is destroyed as it wouldn't be placed in the cache.
+  EXPECT_TRUE(delete_observer_rfh_a.deleted());
+}
+
+IN_PROC_BROWSER_TEST_F(ExtensionBackForwardCacheBrowserTest, CSSAllowed) {
+  ASSERT_TRUE(LoadExtension(test_data_dir_.AppendASCII("back_forward_cache")
+                                .AppendASCII("content_css")));
+
+  ASSERT_TRUE(embedded_test_server()->Start());
+  GURL url_a(embedded_test_server()->GetURL("a.com", "/title1.html"));
+  GURL url_b(embedded_test_server()->GetURL("b.com", "/title1.html"));
+
+  // 1) Navigate to A.
+  content::RenderFrameHost* rfh_a =
+      ui_test_utils::NavigateToURL(browser(), url_a);
+  content::RenderFrameDeletedObserver delete_observer_rfh_a(rfh_a);
+
+  // 2) Navigate to B.
+  content::RenderFrameHost* rfh_b =
+      ui_test_utils::NavigateToURL(browser(), url_b);
+  content::RenderFrameDeletedObserver delete_observer_rfh_b(rfh_b);
+
+  // Ensure that |rfh_a| is in the cache.
+  EXPECT_FALSE(delete_observer_rfh_a.deleted());
+  EXPECT_NE(rfh_a, rfh_b);
+  EXPECT_TRUE(rfh_a->IsInBackForwardCache());
+}
+
+}  // namespace extensions
diff --git a/chrome/renderer/cart/commerce_hint_agent.cc b/chrome/renderer/cart/commerce_hint_agent.cc
index d684c458282783..8fed647a0ccf60 100644
--- a/chrome/renderer/cart/commerce_hint_agent.cc
+++ b/chrome/renderer/cart/commerce_hint_agent.cc
@@ -439,7 +439,8 @@ void CommerceHintAgent::ExtractProducts() {
       new JavaScriptRequest(weak_factory_.GetWeakPtr());
   main_frame->RequestExecuteScriptInIsolatedWorld(
       ISOLATED_WORLD_ID_CHROME_INTERNAL, &source, 1, false,
-      blink::WebLocalFrame::kAsynchronous, request);
+      blink::WebLocalFrame::kAsynchronous, request,
+      blink::BackForwardCacheAware::kAllow);
 }
 
 CommerceHintAgent::JavaScriptRequest::JavaScriptRequest(
diff --git a/chrome/test/BUILD.gn b/chrome/test/BUILD.gn
index 3e710461ace193..ab8c7bdf6fb6e1 100644
--- a/chrome/test/BUILD.gn
+++ b/chrome/test/BUILD.gn
@@ -2042,6 +2042,7 @@ if (!is_android) {
         "../browser/extensions/app_process_apitest.cc",
         "../browser/extensions/app_window_overrides_browsertest.cc",
         "../browser/extensions/autoplay_browsertest.cc",
+        "../browser/extensions/back_forward_cache_browsertest.cc",
         "../browser/extensions/background_header_browsertest.cc",
         "../browser/extensions/background_page_apitest.cc",
         "../browser/extensions/background_scripts_apitest.cc",
diff --git a/chrome/test/data/extensions/back_forward_cache/content_css/color.css b/chrome/test/data/extensions/back_forward_cache/content_css/color.css
new file mode 100644
index 00000000000000..bab6c7a230e429
--- /dev/null
+++ b/chrome/test/data/extensions/back_forward_cache/content_css/color.css
@@ -0,0 +1,5 @@
+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+body {background-color: cyan;}
diff --git a/chrome/test/data/extensions/back_forward_cache/content_css/manifest.json b/chrome/test/data/extensions/back_forward_cache/content_css/manifest.json
new file mode 100644
index 00000000000000..8d1041526861bf
--- /dev/null
+++ b/chrome/test/data/extensions/back_forward_cache/content_css/manifest.json
@@ -0,0 +1,14 @@
+{
+  "name": "no caching",
+  "version": "0.1",
+  "manifest_version": 2,
+  "description": "Checks that injected CSS do prevent back forward cache.",
+  "permissions": ["http://*/*", "https://*/*"],
+  "content_scripts": [
+    {
+      "matches": ["http://*/*", "https://*/*"],
+      "css": ["color.css"],
+      "run_at": "document_start"
+    }
+  ]
+}
diff --git a/chrome/test/data/extensions/back_forward_cache/content_script/change_page_title.js b/chrome/test/data/extensions/back_forward_cache/content_script/change_page_title.js
new file mode 100644
index 00000000000000..f4e4ab13e97b37
--- /dev/null
+++ b/chrome/test/data/extensions/back_forward_cache/content_script/change_page_title.js
@@ -0,0 +1,5 @@
+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+document.title = "modified";
diff --git a/chrome/test/data/extensions/back_forward_cache/content_script/manifest.json b/chrome/test/data/extensions/back_forward_cache/content_script/manifest.json
new file mode 100644
index 00000000000000..369cf50c391578
--- /dev/null
+++ b/chrome/test/data/extensions/back_forward_cache/content_script/manifest.json
@@ -0,0 +1,14 @@
+{
+  "name": "no caching",
+  "version": "0.1",
+  "manifest_version": 2,
+  "description": "Checks that content scripts do prevent back forward cache.",
+  "permissions": ["http://*/*", "https://*/*"],
+  "content_scripts": [
+    {
+      "matches": ["http://*/*", "https://*/*"],
+      "js": ["change_page_title.js"],
+      "run_at": "document_end"
+    }
+  ]
+}
diff --git a/components/translate/content/renderer/per_frame_translate_agent.cc b/components/translate/content/renderer/per_frame_translate_agent.cc
index 3b9a93191c3c2c..d01f0ea0a139fe 100644
--- a/components/translate/content/renderer/per_frame_translate_agent.cc
+++ b/components/translate/content/renderer/per_frame_translate_agent.cc
@@ -200,7 +200,8 @@ void PerFrameTranslateAgent::ExecuteScript(const std::string& script) {
     return;
 
   WebScriptSource source = WebScriptSource(WebString::FromASCII(script));
-  local_frame->ExecuteScriptInIsolatedWorld(world_id_, source);
+  local_frame->ExecuteScriptInIsolatedWorld(
+      world_id_, source, blink::BackForwardCacheAware::kAllow);
 }
 
 bool PerFrameTranslateAgent::ExecuteScriptAndGetBoolResult(
@@ -214,8 +215,8 @@ bool PerFrameTranslateAgent::ExecuteScriptAndGetBoolResult(
   v8::HandleScope handle_scope(v8::Isolate::GetCurrent());
   WebScriptSource source = WebScriptSource(WebString::FromASCII(script));
   v8::Local<v8::Value> result =
-      local_frame->ExecuteScriptInIsolatedWorldAndReturnValue(world_id_,
-                                                              source);
+      local_frame->ExecuteScriptInIsolatedWorldAndReturnValue(
+          world_id_, source, blink::BackForwardCacheAware::kAllow);
   DCHECK(result->IsBoolean());
 
   return result.As<v8::Boolean>()->Value();
@@ -232,8 +233,8 @@ std::string PerFrameTranslateAgent::ExecuteScriptAndGetStringResult(
   v8::HandleScope handle_scope(isolate);
   WebScriptSource source = WebScriptSource(WebString::FromASCII(script));
   v8::Local<v8::Value> result =
-      local_frame->ExecuteScriptInIsolatedWorldAndReturnValue(world_id_,
-                                                              source);
+      local_frame->ExecuteScriptInIsolatedWorldAndReturnValue(
+          world_id_, source, blink::BackForwardCacheAware::kAllow);
   DCHECK(result->IsString());
 
   v8::Local<v8::String> v8_str = result.As<v8::String>();
@@ -253,8 +254,8 @@ double PerFrameTranslateAgent::ExecuteScriptAndGetDoubleResult(
   v8::HandleScope handle_scope(v8::Isolate::GetCurrent());
   WebScriptSource source = WebScriptSource(WebString::FromASCII(script));
   v8::Local<v8::Value> result =
-      local_frame->ExecuteScriptInIsolatedWorldAndReturnValue(world_id_,
-                                                              source);
+      local_frame->ExecuteScriptInIsolatedWorldAndReturnValue(
+          world_id_, source, blink::BackForwardCacheAware::kAllow);
   DCHECK(result->IsNumber());
 
   return result.As<v8::Number>()->Value();
@@ -270,8 +271,8 @@ int64_t PerFrameTranslateAgent::ExecuteScriptAndGetIntegerResult(
   v8::HandleScope handle_scope(v8::Isolate::GetCurrent());
   WebScriptSource source = WebScriptSource(WebString::FromASCII(script));
   v8::Local<v8::Value> result =
-      local_frame->ExecuteScriptInIsolatedWorldAndReturnValue(world_id_,
-                                                              source);
+      local_frame->ExecuteScriptInIsolatedWorldAndReturnValue(
+          world_id_, source, blink::BackForwardCacheAware::kAllow);
   DCHECK(result->IsNumber());
 
   return result.As<v8::Integer>()->Value();
diff --git a/components/translate/content/renderer/translate_agent.cc b/components/translate/content/renderer/translate_agent.cc
index 85acd978e4348c..a05badb8559e63 100644
--- a/components/translate/content/renderer/translate_agent.cc
+++ b/components/translate/content/renderer/translate_agent.cc
@@ -250,7 +250,8 @@ void TranslateAgent::ExecuteScript(const std::string& script) {
     return;
 
   WebScriptSource source = WebScriptSource(WebString::FromASCII(script));
-  main_frame->ExecuteScriptInIsolatedWorld(world_id_, source);
+  main_frame->ExecuteScriptInIsolatedWorld(
+      world_id_, source, blink::BackForwardCacheAware::kAllow);
 }
 
 bool TranslateAgent::ExecuteScriptAndGetBoolResult(const std::string& script,
@@ -262,7 +263,8 @@ bool TranslateAgent::ExecuteScriptAndGetBoolResult(const std::string& script,
   v8::HandleScope handle_scope(v8::Isolate::GetCurrent());
   WebScriptSource source = WebScriptSource(WebString::FromASCII(script));
   v8::Local<v8::Value> result =
-      main_frame->ExecuteScriptInIsolatedWorldAndReturnValue(world_id_, source);
+      main_frame->ExecuteScriptInIsolatedWorldAndReturnValue(
+          world_id_, source, blink::BackForwardCacheAware::kAllow);
   if (result.IsEmpty() || !result->IsBoolean()) {
     NOTREACHED();
     return fallback;
@@ -281,7 +283,8 @@ std::string TranslateAgent::ExecuteScriptAndGetStringResult(
   v8::HandleScope handle_scope(isolate);
   WebScriptSource source = WebScriptSource(WebString::FromASCII(script));
   v8::Local<v8::Value> result =
-      main_frame->ExecuteScriptInIsolatedWorldAndReturnValue(world_id_, source);
+      main_frame->ExecuteScriptInIsolatedWorldAndReturnValue(
+          world_id_, source, blink::BackForwardCacheAware::kAllow);
   if (result.IsEmpty() || !result->IsString()) {
     NOTREACHED();
     return std::string();
@@ -306,7 +309,8 @@ double TranslateAgent::ExecuteScriptAndGetDoubleResult(
   v8::HandleScope handle_scope(v8::Isolate::GetCurrent());
   WebScriptSource source = WebScriptSource(WebString::FromASCII(script));
   v8::Local<v8::Value> result =
-      main_frame->ExecuteScriptInIsolatedWorldAndReturnValue(world_id_, source);
+      main_frame->ExecuteScriptInIsolatedWorldAndReturnValue(
+          world_id_, source, blink::BackForwardCacheAware::kAllow);
   if (result.IsEmpty() || !result->IsNumber()) {
     NOTREACHED();
     return 0.0;
@@ -324,7 +328,8 @@ int64_t TranslateAgent::ExecuteScriptAndGetIntegerResult(
   v8::HandleScope handle_scope(v8::Isolate::GetCurrent());
   WebScriptSource source = WebScriptSource(WebString::FromASCII(script));
   v8::Local<v8::Value> result =
-      main_frame->ExecuteScriptInIsolatedWorldAndReturnValue(world_id_, source);
+      main_frame->ExecuteScriptInIsolatedWorldAndReturnValue(
+          world_id_, source, blink::BackForwardCacheAware::kAllow);
   if (result.IsEmpty() || !result->IsNumber()) {
     NOTREACHED();
     return 0;
diff --git a/content/browser/renderer_host/back_forward_cache_impl.cc b/content/browser/renderer_host/back_forward_cache_impl.cc
index a229a72e8cf565..e653db8d3bc006 100644
--- a/content/browser/renderer_host/back_forward_cache_impl.cc
+++ b/content/browser/renderer_host/back_forward_cache_impl.cc
@@ -99,6 +99,14 @@ bool IsGeolocationSupported() {
   return geolocation_supported.Get();
 }
 
+bool IsContentInjectionSupported() {
+  if (!IsBackForwardCacheEnabled())
+    return false;
+  static constexpr base::FeatureParam<bool> content_injection_supported(
+      &features::kBackForwardCache, "content_injection_supported", false);
+  return content_injection_supported.Get();
+}
+
 bool IsFileSystemSupported() {
   if (!IsBackForwardCacheEnabled())
     return false;
@@ -204,6 +212,11 @@ uint64_t GetDisallowedFeatures(RenderFrameHostImpl* rfh,
         WebSchedulerTrackedFeature::kRequestedGeolocationPermission);
   }
 
+  if (!IsContentInjectionSupported()) {
+    result |= FeatureToBit(WebSchedulerTrackedFeature::kIsolatedWorldScript) |
+              FeatureToBit(WebSchedulerTrackedFeature::kInjectedStyleSheet);
+  }
+
   if (!IgnoresOutstandingNetworkRequestForTesting()) {
     result |=
         FeatureToBit(
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 580974507f1a30..2810ba8bee7647 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -2446,7 +2446,8 @@ void RenderFrameImpl::JavaScriptExecuteRequestForTests(
         WebScriptSource(WebString::FromUTF16(javascript)));
   } else {
     result = frame_->ExecuteScriptInIsolatedWorldAndReturnValue(
-        world_id, WebScriptSource(WebString::FromUTF16(javascript)));
+        world_id, WebScriptSource(WebString::FromUTF16(javascript)),
+        blink::BackForwardCacheAware::kAllow);
   }
 
   if (!weak_this)
@@ -2481,7 +2482,8 @@ void RenderFrameImpl::JavaScriptExecuteRequestInIsolatedWorld(
   JavaScriptIsolatedWorldRequest* request = new JavaScriptIsolatedWorldRequest(
       weak_factory_.GetWeakPtr(), wants_result, std::move(callback));
   frame_->RequestExecuteScriptInIsolatedWorld(
-      world_id, &script, 1, false, WebLocalFrame::kSynchronous, request);
+      world_id, &script, 1, false, WebLocalFrame::kSynchronous, request,
+      blink::BackForwardCacheAware::kAllow);
 }
 
 RenderFrameImpl::JavaScriptIsolatedWorldRequest::JavaScriptIsolatedWorldRequest(
diff --git a/content/web_test/renderer/test_runner.cc b/content/web_test/renderer/test_runner.cc
index 4a5ecbda970ac2..166a49c770fc59 100644
--- a/content/web_test/renderer/test_runner.cc
+++ b/content/web_test/renderer/test_runner.cc
@@ -1075,8 +1075,8 @@ TestRunnerBindings::EvaluateScriptInIsolatedWorldAndReturnValue(
     return {};
 
   blink::WebScriptSource source = blink::WebString::FromUTF8(script);
-  return GetWebFrame()->ExecuteScriptInIsolatedWorldAndReturnValue(world_id,
-                                                                   source);
+  return GetWebFrame()->ExecuteScriptInIsolatedWorldAndReturnValue(
+      world_id, source, blink::BackForwardCacheAware::kAllow);
 }
 
 void TestRunnerBindings::EvaluateScriptInIsolatedWorld(
@@ -1086,7 +1086,8 @@ void TestRunnerBindings::EvaluateScriptInIsolatedWorld(
     return;
 
   blink::WebScriptSource source = blink::WebString::FromUTF8(script);
-  GetWebFrame()->ExecuteScriptInIsolatedWorld(world_id, source);
+  GetWebFrame()->ExecuteScriptInIsolatedWorld(
+      world_id, source, blink::BackForwardCacheAware::kAllow);
 }
 
 void TestRunnerBindings::SetIsolatedWorldInfo(
diff --git a/extensions/renderer/script_injection.cc b/extensions/renderer/script_injection.cc
index d9a28ff7598363..a66860efaae403 100644
--- a/extensions/renderer/script_injection.cc
+++ b/extensions/renderer/script_injection.cc
@@ -336,7 +336,8 @@ void ScriptInjection::InjectJs(std::set<std::string>* executing_scripts,
 
   render_frame_->GetWebFrame()->RequestExecuteScriptInIsolatedWorld(
       world_id, &sources.front(), sources.size(), is_user_gesture,
-      execution_option, callback.release());
+      execution_option, callback.release(),
+      blink::BackForwardCacheAware::kPossiblyDisallow);
 }
 
 void ScriptInjection::OnJsInjectionCompleted(
@@ -436,8 +437,9 @@ void ScriptInjection::InjectOrRemoveCss(
   } else {
     DCHECK(adding_css);
     for (const blink::WebString& css : css_sources)
-      web_frame->GetDocument().InsertStyleSheet(css, &style_sheet_key,
-                                                blink_css_origin);
+      web_frame->GetDocument().InsertStyleSheet(
+          css, &style_sheet_key, blink_css_origin,
+          blink::BackForwardCacheAware::kPossiblyDisallow);
   }
 }
 
diff --git a/third_party/blink/common/scheduler/web_scheduler_tracked_feature.cc b/third_party/blink/common/scheduler/web_scheduler_tracked_feature.cc
index ad0dd40c2365e5..8783d916d7f22f 100644
--- a/third_party/blink/common/scheduler/web_scheduler_tracked_feature.cc
+++ b/third_party/blink/common/scheduler/web_scheduler_tracked_feature.cc
@@ -133,6 +133,10 @@ FeatureNames FeatureToNames(WebSchedulerTrackedFeature feature) {
     case WebSchedulerTrackedFeature::kOutstandingNetworkRequestDirectSocket:
       return {"OutstandingNetworkRequestDirectSocket",
               "outstanding network request (direct socket)"};
+    case WebSchedulerTrackedFeature::kIsolatedWorldScript:
+      return {"IsolatedWorldScript", "Isolated world ran script"};
+    case WebSchedulerTrackedFeature::kInjectedStyleSheet:
+      return {"InjectedStyleSheet", "External systesheet injected"};
   }
   return {};
 }
@@ -218,7 +222,9 @@ uint64_t StickyFeaturesBitmask() {
          FeatureToBit(WebSchedulerTrackedFeature::kIdleManager) |
          FeatureToBit(WebSchedulerTrackedFeature::kPaymentManager) |
          FeatureToBit(WebSchedulerTrackedFeature::kKeyboardLock) |
-         FeatureToBit(WebSchedulerTrackedFeature::kWebOTPService);
+         FeatureToBit(WebSchedulerTrackedFeature::kWebOTPService) |
+         FeatureToBit(WebSchedulerTrackedFeature::kIsolatedWorldScript) |
+         FeatureToBit(WebSchedulerTrackedFeature::kInjectedStyleSheet);
 }
 
 }  // namespace scheduler
diff --git a/third_party/blink/public/common/scheduler/web_scheduler_tracked_feature.h b/third_party/blink/public/common/scheduler/web_scheduler_tracked_feature.h
index d7dfda5cadd930..5a13da1c0a5271 100644
--- a/third_party/blink/public/common/scheduler/web_scheduler_tracked_feature.h
+++ b/third_party/blink/public/common/scheduler/web_scheduler_tracked_feature.h
@@ -100,9 +100,11 @@ enum class WebSchedulerTrackedFeature : uint32_t {
   kKeyboardLock = 51,
   kWebOTPService = 52,
   kOutstandingNetworkRequestDirectSocket = 53,
+  kIsolatedWorldScript = 54,
+  kInjectedStyleSheet = 55,
 
   // NB: This enum is used in a bitmask, so kMaxValue must be less than 64.
-  kMaxValue = kOutstandingNetworkRequestDirectSocket
+  kMaxValue = kInjectedStyleSheet
 };
 
 static_assert(static_cast<uint32_t>(WebSchedulerTrackedFeature::kMaxValue) < 64,
diff --git a/third_party/blink/public/web/web_document.h b/third_party/blink/public/web/web_document.h
index b6f3b4e3b8dae2..d181ff3be4608a 100644
--- a/third_party/blink/public/web/web_document.h
+++ b/third_party/blink/public/web/web_document.h
@@ -53,6 +53,13 @@ struct WebDistillabilityFeatures;
 
 using WebStyleSheetKey = WebString;
 
+// An enumeration used to enumerate usage of APIs that may prevent a document
+// from entering the back forward cache. |kAllow| means usage of the API will
+// not restrict the back forward cache. |kPossiblyDisallow| means usage of the
+// API will be marked as such and the back forward cache may not allow the
+// document to enter at its discretion.
+enum class BackForwardCacheAware { kAllow, kPossiblyDisallow };
+
 // Provides readonly access to some properties of a DOM document.
 class WebDocument : public WebNode {
  public:
@@ -106,10 +113,11 @@ class WebDocument : public WebNode {
   BLINK_EXPORT WebElement FocusedElement() const;
 
   // Inserts the given CSS source code as a style sheet in the document.
-  BLINK_EXPORT WebStyleSheetKey InsertStyleSheet(
-      const WebString& source_code,
-      const WebStyleSheetKey* = nullptr,
-      CSSOrigin = kAuthorOrigin);
+  BLINK_EXPORT WebStyleSheetKey
+  InsertStyleSheet(const WebString& source_code,
+                   const WebStyleSheetKey* = nullptr,
+                   CSSOrigin = kAuthorOrigin,
+                   BackForwardCacheAware = BackForwardCacheAware::kAllow);
 
   // Removes the CSS which was previously inserted by a call to
   // InsertStyleSheet().
diff --git a/third_party/blink/public/web/web_local_frame.h b/third_party/blink/public/web/web_local_frame.h
index 50702c6c3a1871..e947d7f412dfe5 100644
--- a/third_party/blink/public/web/web_local_frame.h
+++ b/third_party/blink/public/web/web_local_frame.h
@@ -39,6 +39,7 @@
 #include "third_party/blink/public/platform/task_type.h"
 #include "third_party/blink/public/platform/web_url_error.h"
 #include "third_party/blink/public/platform/web_url_request.h"
+#include "third_party/blink/public/web/web_document.h"
 #include "third_party/blink/public/web/web_document_loader.h"
 #include "third_party/blink/public/web/web_frame.h"
 #include "third_party/blink/public/web/web_frame_load_type.h"
@@ -72,7 +73,6 @@ class WebAssociatedURLLoader;
 class WebAutofillClient;
 class WebContentCaptureClient;
 class WebContentSettingsClient;
-class WebDocument;
 class WebLocalFrameClient;
 class WebFrameWidget;
 class WebHistoryItem;
@@ -324,14 +324,16 @@ class WebLocalFrame : public WebFrame {
   // worldID must be > 0 (as 0 represents the main world).
   // worldID must be < kEmbedderWorldIdLimit, high number used internally.
   virtual void ExecuteScriptInIsolatedWorld(int32_t world_id,
-                                            const WebScriptSource&) = 0;
+                                            const WebScriptSource&,
+                                            BackForwardCacheAware) = 0;
 
   // worldID must be > 0 (as 0 represents the main world).
   // worldID must be < kEmbedderWorldIdLimit, high number used internally.
   // DEPRECATED: Use WebLocalFrame::requestExecuteScriptInIsolatedWorld.
   WARN_UNUSED_RESULT virtual v8::Local<v8::Value>
   ExecuteScriptInIsolatedWorldAndReturnValue(int32_t world_id,
-                                             const WebScriptSource&) = 0;
+                                             const WebScriptSource&,
+                                             BackForwardCacheAware) = 0;
 
   // Clears the isolated world CSP stored for |world_id| by this frame's
   // Document.
@@ -404,7 +406,8 @@ class WebLocalFrame : public WebFrame {
       unsigned num_sources,
       bool user_gesture,
       ScriptExecutionType,
-      WebScriptExecutionCallback*) = 0;
+      WebScriptExecutionCallback*,
+      BackForwardCacheAware) = 0;
 
   // Logs to the console associated with this frame. If |discard_duplicates| is
   // set, the message will only be added if it is unique (i.e. has not been
diff --git a/third_party/blink/renderer/bindings/core/v8/window_proxy_test.cc b/third_party/blink/renderer/bindings/core/v8/window_proxy_test.cc
index ca16c31ce9d3ad..a09d16b0684e9d 100644
--- a/third_party/blink/renderer/bindings/core/v8/window_proxy_test.cc
+++ b/third_party/blink/renderer/bindings/core/v8/window_proxy_test.cc
@@ -68,13 +68,15 @@ TEST_F(WindowProxyTest, IsolatedWorldReinitializedAfterNavigation) {
   // Save a reference to the top `window` in the isolated world.
   v8::Local<v8::Value> window_top =
       MainFrame().ExecuteScriptInIsolatedWorldAndReturnValue(
-          kIsolatedWorldId, WebScriptSource("window"));
+          kIsolatedWorldId, WebScriptSource("window"),
+          BackForwardCacheAware::kAllow);
   ASSERT_TRUE(window_top->IsObject());
 
   // Save a reference to the child frame's window proxy in the isolated world.
   v8::Local<v8::Value> saved_child_window =
       MainFrame().ExecuteScriptInIsolatedWorldAndReturnValue(
-          kIsolatedWorldId, WebScriptSource("saved = window[0]"));
+          kIsolatedWorldId, WebScriptSource("saved = window[0]"),
+          BackForwardCacheAware::kAllow);
   ASSERT_TRUE(saved_child_window->IsObject());
 
   frame_test_helpers::LoadFrame(MainFrame().FirstChild()->ToWebLocalFrame(),
@@ -87,7 +89,8 @@ TEST_F(WindowProxyTest, IsolatedWorldReinitializedAfterNavigation) {
   // cached earlier.
   v8::Local<v8::Value> top_via_saved =
       MainFrame().ExecuteScriptInIsolatedWorldAndReturnValue(
-          kIsolatedWorldId, WebScriptSource("saved.top"));
+          kIsolatedWorldId, WebScriptSource("saved.top"),
+          BackForwardCacheAware::kAllow);
   EXPECT_TRUE(top_via_saved->IsObject());
   EXPECT_TRUE(window_top->StrictEquals(top_via_saved));
 }
diff --git a/third_party/blink/renderer/core/exported/web_document.cc b/third_party/blink/renderer/core/exported/web_document.cc
index 739e0f95e37e69..a2c1db262ff05c 100644
--- a/third_party/blink/renderer/core/exported/web_document.cc
+++ b/third_party/blink/renderer/core/exported/web_document.cc
@@ -207,11 +207,18 @@ WebElement WebDocument::FocusedElement() const {
   return WebElement(ConstUnwrap<Document>()->FocusedElement());
 }
 
-WebStyleSheetKey WebDocument::InsertStyleSheet(const WebString& source_code,
-                                               const WebStyleSheetKey* key,
-                                               CSSOrigin origin) {
+WebStyleSheetKey WebDocument::InsertStyleSheet(
+    const WebString& source_code,
+    const WebStyleSheetKey* key,
+    CSSOrigin origin,
+    BackForwardCacheAware back_forward_cache_aware) {
   Document* document = Unwrap<Document>();
   DCHECK(document);
+  if (back_forward_cache_aware == BackForwardCacheAware::kPossiblyDisallow) {
+    document->GetFrame()->GetFrameScheduler()->RegisterStickyFeature(
+        SchedulingPolicy::Feature::kInjectedStyleSheet,
+        {SchedulingPolicy::DisableBackForwardCache()});
+  }
   auto* parsed_sheet = MakeGarbageCollected<StyleSheetContents>(
       MakeGarbageCollected<CSSParserContext>(*document));
   parsed_sheet->ParseString(source_code);
diff --git a/third_party/blink/renderer/core/frame/web_frame_test.cc b/third_party/blink/renderer/core/frame/web_frame_test.cc
index ba23dee2970d57..3ea95962c4248e 100644
--- a/third_party/blink/renderer/core/frame/web_frame_test.cc
+++ b/third_party/blink/renderer/core/frame/web_frame_test.cc
@@ -4602,7 +4602,7 @@ TEST_F(WebFrameTest, ContextNotificationsIsolatedWorlds) {
   int32_t isolated_world_id = 42;
   WebScriptSource script_source("hi!");
   web_view_helper.LocalMainFrame()->ExecuteScriptInIsolatedWorld(
-      isolated_world_id, script_source);
+      isolated_world_id, script_source, BackForwardCacheAware::kAllow);
 
   // We should now have a new create notification.
   ASSERT_EQ(1u, create_notifications.size());
diff --git a/third_party/blink/renderer/core/frame/web_local_frame_impl.cc b/third_party/blink/renderer/core/frame/web_local_frame_impl.cc
index 80f58a5f2762fa..82b127eaabf813 100644
--- a/third_party/blink/renderer/core/frame/web_local_frame_impl.cc
+++ b/third_party/blink/renderer/core/frame/web_local_frame_impl.cc
@@ -864,11 +864,18 @@ void WebLocalFrameImpl::ExecuteScript(const WebScriptSource& source) {
 
 void WebLocalFrameImpl::ExecuteScriptInIsolatedWorld(
     int32_t world_id,
-    const WebScriptSource& source_in) {
+    const WebScriptSource& source_in,
+    BackForwardCacheAware back_forward_cache_aware) {
   DCHECK(GetFrame());
   CHECK_GT(world_id, DOMWrapperWorld::kMainWorldId);
   CHECK_LT(world_id, DOMWrapperWorld::kDOMWrapperWorldEmbedderWorldIdLimit);
 
+  if (back_forward_cache_aware == BackForwardCacheAware::kPossiblyDisallow) {
+    GetFrame()->GetFrameScheduler()->RegisterStickyFeature(
+        SchedulingPolicy::Feature::kIsolatedWorldScript,
+        {SchedulingPolicy::DisableBackForwardCache()});
+  }
+
   // Note: An error event in an isolated world will never be dispatched to
   // a foreign world.
   v8::HandleScope handle_scope(ToIsolate(GetFrame()));
@@ -881,11 +888,18 @@ void WebLocalFrameImpl::ExecuteScriptInIsolatedWorld(
 v8::Local<v8::Value>
 WebLocalFrameImpl::ExecuteScriptInIsolatedWorldAndReturnValue(
     int32_t world_id,
-    const WebScriptSource& source_in) {
+    const WebScriptSource& source_in,
+    BackForwardCacheAware back_forward_cache_aware) {
   DCHECK(GetFrame());
   CHECK_GT(world_id, DOMWrapperWorld::kMainWorldId);
   CHECK_LT(world_id, DOMWrapperWorld::kDOMWrapperWorldEmbedderWorldIdLimit);
 
+  if (back_forward_cache_aware == BackForwardCacheAware::kPossiblyDisallow) {
+    GetFrame()->GetFrameScheduler()->RegisterStickyFeature(
+        SchedulingPolicy::Feature::kIsolatedWorldScript,
+        {SchedulingPolicy::DisableBackForwardCache()});
+  }
+
   // Note: An error event in an isolated world will never be dispatched to
   // a foreign world.
   return ClassicScript::CreateUnspecifiedScript(
@@ -987,11 +1001,18 @@ void WebLocalFrameImpl::RequestExecuteScriptInIsolatedWorld(
     unsigned num_sources,
     bool user_gesture,
     ScriptExecutionType option,
-    WebScriptExecutionCallback* callback) {
+    WebScriptExecutionCallback* callback,
+    BackForwardCacheAware back_forward_cache_aware) {
   DCHECK(GetFrame());
   CHECK_GT(world_id, DOMWrapperWorld::kMainWorldId);
   CHECK_LT(world_id, DOMWrapperWorld::kDOMWrapperWorldEmbedderWorldIdLimit);
 
+  if (back_forward_cache_aware == BackForwardCacheAware::kPossiblyDisallow) {
+    GetFrame()->GetFrameScheduler()->RegisterStickyFeature(
+        SchedulingPolicy::Feature::kIsolatedWorldScript,
+        {SchedulingPolicy::DisableBackForwardCache()});
+  }
+
   scoped_refptr<DOMWrapperWorld> isolated_world =
       DOMWrapperWorld::EnsureIsolatedWorld(ToIsolate(GetFrame()), world_id);
   auto* executor = MakeGarbageCollected<PausableScriptExecutor>(
diff --git a/third_party/blink/renderer/core/frame/web_local_frame_impl.h b/third_party/blink/renderer/core/frame/web_local_frame_impl.h
index 04035ce2827f28..a7266407e593d9 100644
--- a/third_party/blink/renderer/core/frame/web_local_frame_impl.h
+++ b/third_party/blink/renderer/core/frame/web_local_frame_impl.h
@@ -144,11 +144,15 @@ class CORE_EXPORT WebLocalFrameImpl final
   void GetPageDescription(uint32_t page_index,
                           WebPrintPageDescription*) override;
   void ExecuteScript(const WebScriptSource&) override;
-  void ExecuteScriptInIsolatedWorld(int32_t world_id,
-                                    const WebScriptSource&) override;
+  void ExecuteScriptInIsolatedWorld(
+      int32_t world_id,
+      const WebScriptSource&,
+      BackForwardCacheAware back_forward_cache_aware) override;
   WARN_UNUSED_RESULT v8::Local<v8::Value>
-  ExecuteScriptInIsolatedWorldAndReturnValue(int32_t world_id,
-                                             const WebScriptSource&) override;
+  ExecuteScriptInIsolatedWorldAndReturnValue(
+      int32_t world_id,
+      const WebScriptSource&,
+      BackForwardCacheAware back_forward_cache_aware) override;
   void ClearIsolatedWorldCSPForTesting(int32_t world_id) override;
   v8::Local<v8::Value> ExecuteScriptAndReturnValue(
       const WebScriptSource&) override;
@@ -181,7 +185,8 @@ class CORE_EXPORT WebLocalFrameImpl final
       unsigned num_sources,
       bool user_gesture,
       ScriptExecutionType,
-      WebScriptExecutionCallback*) override;
+      WebScriptExecutionCallback*,
+      BackForwardCacheAware back_forward_cache_aware) override;
   void Alert(const WebString& message) override;
   bool Confirm(const WebString& message) override;
   WebString Prompt(const WebString& message,
diff --git a/tools/metrics/histograms/enums.xml b/tools/metrics/histograms/enums.xml
index 68b17a3670262d..6d720f3dbe48fe 100644
--- a/tools/metrics/histograms/enums.xml
+++ b/tools/metrics/histograms/enums.xml
@@ -82128,6 +82128,8 @@ Called by update_scheduler_enums.py.-->
   <int value="51" label="KeyboardLock"/>
   <int value="52" label="WebOTPService"/>
   <int value="53" label="OutstandingNetworkRequestDirectSocket"/>
+  <int value="54" label="IsolatedWorldScript"/>
+  <int value="55" label="ExtensionStyleSheet"/>
 </enum>
 
 <enum name="WebShareMethod">