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

chrome/renderer/net/net_error_helper.h

 // Copyright (c) 2013 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 CHROME_RENDERER_NET_NET_ERROR_HELPER_H_
 #define CHROME_RENDERER_NET_NET_ERROR_HELPER_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 38 matching lines @@
       public chrome::mojom::NetworkDiagnosticsClient {
  public:
   explicit NetErrorHelper(content::RenderFrame* render_frame);
   ~NetErrorHelper() override;
 
   // NetErrorPageController::Delegate implementation
   void ButtonPressed(error_page::NetErrorHelperCore::Button button) override;
   void TrackClick(int tracking_id) override;
 
   // RenderFrameObserver implementation.
-  void DidStartProvisionalLoad() override;
+  void DidStartProvisionalLoad(blink::WebDataSource* data_source) override;
   void DidCommitProvisionalLoad(bool is_new_navigation,
                                 bool is_same_page_navigation) override;
   void DidFinishLoad() override;
   void OnStop() override;
   void WasShown() override;
   void WasHidden() override;
   void OnDestruct() override;
 
   // IPC::Listener implementation.
   bool OnMessageReceived(const IPC::Message& message) override;
@@ skipping 75 matching lines @@
   // Weak factory for vending a weak pointer to a NetErrorPageController. Weak
   // pointers are invalidated on each commit, to prevent getting messages from
   // Controllers used for the previous commit that haven't yet been cleaned up.
   base::WeakPtrFactory<NetErrorPageController::Delegate>
       weak_controller_delegate_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NetErrorHelper);
 };
 
 #endif  // CHROME_RENDERER_NET_NET_ERROR_HELPER_H_