Re-enable simplechrome on tryserver.

The builders are passing and building non-buggy targets now, so this should
be safe.

BUG=chromium:503659
TEST=None

Review URL: https://codereview.chromium.org/1210353005

Cr-Commit-Position: refs/heads/master@{#339352}

infra/config/cq.cfg

@@ -36,18 +36,9 @@ verifiers {
       builders { name: "android_compile_dbg" }
       builders { name: "cast_shell_android" }
       builders { name: "cast_shell_linux" }
-      builders {
-        name: "chromeos_x86-generic_chromium_compile_only_ng"
-        experiment_percentage: 1.0
-      }
-      builders {
-        name: "chromeos_amd64-generic_chromium_compile_only_ng"
-        experiment_percentage: 1.0
-      }
-      builders {
-        name: "chromeos_daisy_chromium_compile_only_ng"
-        experiment_percentage: 1.0
-      }
+      builders { name: "chromeos_x86-generic_chromium_compile_only_ng" }
+      builders { name: "chromeos_amd64-generic_chromium_compile_only_ng" }
+      builders { name: "chromeos_daisy_chromium_compile_only_ng" }
       builders { name: "chromium_presubmit" }
       builders { name: "linux_android_rel_ng" }
       builders { name: "linux_arm_compile" }