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

components/dom_distiller/content/renderer/distiller_js_render_frame_observer.h

 // Copyright 2015 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_DOM_DISTILLER_CONTENT_RENDERER_DISTILLER_JS_RENDER_FRAME_OBSERVER_H_
 #define COMPONENTS_DOM_DISTILLER_CONTENT_RENDERER_DISTILLER_JS_RENDER_FRAME_OBSERVER_H_
 
 #include "base/memory/weak_ptr.h"
 #include "components/dom_distiller/content/common/distiller_javascript_service.mojom.h"
 #include "components/dom_distiller/content/renderer/distiller_native_javascript.h"
 #include "components/dom_distiller/content/renderer/distiller_page_notifier_service_impl.h"
 #include "content/public/renderer/render_frame.h"
 #include "content/public/renderer/render_frame_observer.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
 #include "v8/include/v8.h"
 
 namespace dom_distiller {
 
 // DistillerJsRenderFrame observer waits for a page to be loaded and then
 // tried to connect to a mojo service hosted in the browser process. The
 // service will tell this render process if the current page is a distiller
 // page.
 class DistillerJsRenderFrameObserver : public content::RenderFrameObserver {
  public:
   DistillerJsRenderFrameObserver(content::RenderFrame* render_frame,
                                  const int distiller_isolated_world_id);
   ~DistillerJsRenderFrameObserver() override;
 
   // RenderFrameObserver implementation.
-  void DidStartProvisionalLoad() override;
+  void DidStartProvisionalLoad(blink::WebDataSource* data_source) override;
   void DidFinishLoad() override;
   void DidCreateScriptContext(v8::Local<v8::Context> context,
                               int world_id) override;
 
   // Add the mojo interface to a RenderFrame's
   // service_manager::InterfaceRegistry.
   void RegisterMojoInterface();
   // Flag the current page as a distiller page.
   void SetIsDistillerPage();
 
@@ skipping 11 matching lines @@
   bool is_distiller_page_;
 
   // Handle to "distiller" JavaScript object functionality.
   std::unique_ptr<DistillerNativeJavaScript> native_javascript_handle_;
   base::WeakPtrFactory<DistillerJsRenderFrameObserver> weak_factory_;
 };
 
 }  // namespace dom_distiller
 
 #endif  // COMPONENTS_DOM_DISTILLER_CONTENT_RENDERER_DISTILLER_JS_RENDER_FRAME_OBSERVER_H_