PlzNavigate: Invoke didStartProvisionalLoad() when the renderer initiates a navigation in startLoad(

components/test_runner/web_frame_test_proxy.h

 // Copyright 2014 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.
 
 #ifndef COMPONENTS_TEST_RUNNER_WEB_FRAME_TEST_PROXY_H_
 #define COMPONENTS_TEST_RUNNER_WEB_FRAME_TEST_PROXY_H_
 
 #include <memory>
 #include <utility>
 
@@ skipping 78 matching lines @@
   void loadURLExternally(const blink::WebURLRequest& request,
                          blink::WebNavigationPolicy policy,
                          const blink::WebString& suggested_name,
                          bool replaces_current_history_item) override {
     test_client()->loadURLExternally(request, policy, suggested_name,
                                      replaces_current_history_item);
     Base::loadURLExternally(request, policy, suggested_name,
                             replaces_current_history_item);
   }
 
-  void didStartProvisionalLoad(blink::WebLocalFrame* frame) override {
-    test_client()->didStartProvisionalLoad(frame);
-    Base::didStartProvisionalLoad(frame);
+  void didStartProvisionalLoad(blink::WebDataSource* data_source) override {
+    test_client()->didStartProvisionalLoad(data_source);
+    Base::didStartProvisionalLoad(data_source);
   }
 
   void didReceiveServerRedirectForProvisionalLoad(
       blink::WebLocalFrame* frame) override {
     test_client()->didReceiveServerRedirectForProvisionalLoad(frame);
     Base::didReceiveServerRedirectForProvisionalLoad(frame);
   }
 
   void didFailProvisionalLoad(
       blink::WebLocalFrame* frame,
@@ skipping 185 matching lines @@
     return test_client()->runFileChooser(params, completion);
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(WebFrameTestProxy);
 };
 
 }  // namespace test_runner
 
 #endif  // COMPONENTS_TEST_RUNNER_WEB_FRAME_TEST_PROXY_H_