Handle api_requests with binary content correctly in Python 3. Added …

…test.

gcloud/storage/connection.py

@@ -235,6 +235,9 @@ def api_request(self, method, path, query_params=None,
         if not 200 <= response.status < 300:
             raise make_exception(response, content)
 
+        if not isinstance(content, str):
+            content = str(content.decode('utf-8'))
+
         if content and expect_json:
             content_type = response.get('content-type', '')
             if not content_type.startswith('application/json'):

gcloud/storage/test_connection.py

@@ -206,6 +206,16 @@ def test_api_request_wo_json_expected(self):
         self.assertEqual(conn.api_request('GET', '/', expect_json=False),
                          'CONTENT')
 
+    def test_api_request_w_binary_json_string(self):
+        PROJECT = 'project'
+        conn = self._makeOne(PROJECT)
+        conn._http = Http(
+            {'status': '200', 'content-type': 'application/json'},
+            b'{"foo": "bar"}'
+        )
+        self.assertEqual(conn.api_request('GET', '/', expect_json=True),
+                         {'foo': 'bar'})
+
     def test_api_request_w_query_params(self):
         from six.moves.urllib.parse import parse_qsl
         from six.moves.urllib.parse import urlsplit