Remove httplib2, replace with Requests (#3674)

* Core: remove httplib2, replace with Requests

Additionally remove make_exception in favor of from_http_status and from_http_response.

* Datastore: replace httplib2 with Requests

* DNS: replace httplib2 with Requests

* Error Reporting: replace httplib2 with requests

* Language: replace httplib2 with Requests

* Logging: replace httplib2 with requests

* Monitoring: replace httplib2 with Requests

* Pubsub: replace httplib2 with Requests

* Resource Manager: replace httplib2 with Requests

* Runtimeconfig: replace httplib2 with Requests

* Speech: replace httplib2 with Requests

* Storage: replace httplib2 with Requests

* BigQuery: replace httplib2 with Requests

* Translate: replace httplib2 with Requests

* Vision: replace httplib2 with Requests

packages/google-cloud-vision/google/cloud/vision/client.py

@@ -43,10 +43,10 @@ class Client(ClientWithProject):
                         passed), falls back to the default inferred from the
                         environment.
 
-    :type _http: :class:`~httplib2.Http`
+    :type _http: :class:`~requests.Session`
     :param _http: (Optional) HTTP object to make requests. Can be any object
                   that defines ``request()`` with the same interface as
-                  :meth:`~httplib2.Http.request`. If not passed, an
+                  :meth:`requests.Session.request`. If not passed, an
                   ``_http`` object is created that is bound to the
                   ``credentials`` for the current object.
                   This parameter should be considered private, and could

packages/google-cloud-vision/tests/unit/test__http.py

@@ -40,13 +40,17 @@ def test_default_url(self):
         self.assertEqual(conn._client, client)
 
     def test_extra_headers(self):
+        import requests
+
         from google.cloud import _http as base_http
         from google.cloud.vision import _http as MUT
 
-        http = mock.Mock(spec=['request'])
-        response = mock.Mock(status=200, spec=['status'])
+        http = mock.create_autospec(requests.Session, instance=True)
+        response = requests.Response()
+        response.status_code = 200
         data = b'brent-spiner'
-        http.request.return_value = response, data
+        response._content = data
+        http.request.return_value = response
         client = mock.Mock(_http=http, spec=['_http'])
 
         conn = self._make_one(client)
@@ -56,17 +60,16 @@ def test_extra_headers(self):
         self.assertEqual(result, data)
 
         expected_headers = {
-            'Content-Length': str(len(req_data)),
             'Accept-Encoding': 'gzip',
             base_http.CLIENT_INFO_HEADER: MUT._CLIENT_INFO,
             'User-Agent': conn.USER_AGENT,
         }
         expected_uri = conn.build_api_url('/rainbow')
         http.request.assert_called_once_with(
-            body=req_data,
+            data=req_data,
             headers=expected_headers,
             method='GET',
-            uri=expected_uri,
+            url=expected_uri,
         )