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

content/public/renderer/render_frame_observer.h

 // Copyright 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 CONTENT_PUBLIC_RENDERER_RENDER_FRAME_OBSERVER_H_
 #define CONTENT_PUBLIC_RENDERER_RENDER_FRAME_OBSERVER_H_
 
 #include <stdint.h>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "content/common/content_export.h"
 #include "ipc/ipc_listener.h"
 #include "ipc/ipc_sender.h"
 #include "third_party/WebKit/public/platform/WebLoadingBehaviorFlag.h"
 #include "third_party/WebKit/public/platform/WebVector.h"
 #include "third_party/WebKit/public/web/WebMeaningfulLayout.h"
 #include "v8/include/v8.h"
 
 namespace blink {
+class WebDataSource;
 class WebFormElement;
 class WebNode;
 class WebString;
 struct WebURLError;
 }
 
 namespace content {
 
 class RendererPpapiHost;
 class RenderFrame;
@@ skipping 23 matching lines @@
   virtual void WidgetWillClose() {}
 
   // These match the Blink API notifications
   virtual void DidCreateNewDocument() {}
   virtual void DidCreateDocumentElement() {}
   // Called when a provisional load is about to commit in a frame. This is
   // dispatched just before the Javascript unload event.
   virtual void WillCommitProvisionalLoad() {}
   virtual void DidCommitProvisionalLoad(bool is_new_navigation,
                                         bool is_same_page_navigation) {}
-  virtual void DidStartProvisionalLoad() {}
+  virtual void DidStartProvisionalLoad(blink::WebDataSource* data_source) {}
   virtual void DidFailProvisionalLoad(const blink::WebURLError& error) {}
   virtual void DidFinishLoad() {}
   virtual void DidFinishDocumentLoad() {}
   virtual void DidCreateScriptContext(v8::Local<v8::Context> context,
                                       int world_id) {}
   virtual void WillReleaseScriptContext(v8::Local<v8::Context> context,
                                         int world_id) {}
   virtual void DidClearWindowObject() {}
   virtual void DidChangeManifest() {}
   virtual void DidChangeScrollOffset() {}
@@ skipping 70 matching lines @@
   RenderFrame* render_frame_;
   // The routing ID of the associated RenderFrame.
   int routing_id_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderFrameObserver);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_RENDERER_RENDER_FRAME_OBSERVER_H_