Refactor TaskManager's favicon retrieval approach

chrome/browser/task_management/providers/web_contents/renderer_task.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 CHROME_BROWSER_TASK_MANAGEMENT_PROVIDERS_WEB_CONTENTS_RENDERER_TASK_H_
 #define CHROME_BROWSER_TASK_MANAGEMENT_PROVIDERS_WEB_CONTENTS_RENDERER_TASK_H_
 
 #include "chrome/browser/task_management/providers/task.h"
+#include "components/favicon/core/favicon_driver_observer.h"
 #include "content/public/browser/navigation_entry.h"
 
 class ProcessResourceUsage;
 
 namespace content {
 class RenderProcessHost;
 class WebContents;
 } // namespace content
 
 namespace task_management {
 
 // Defines an abstract base class for various types of renderer process tasks
 // such as background contents, tab contents, ... etc.
-class RendererTask : public Task {
+class RendererTask : public Task,
+                     public favicon::FaviconDriverObserver {
  public:
   RendererTask(const base::string16& title,
                const gfx::ImageSkia* icon,
                content::WebContents* web_contents,
                content::RenderProcessHost* render_process_host);
   ~RendererTask() override;
 
   // An abstract method that will be called when the event
   // WebContentsObserver::DidNavigateMainFrame() occurs. This gives the
   // freedom to concrete tasks to adjust the title however they need to before
   // they set it.
   virtual void UpdateTitle() = 0;
 
   // An abstract method that will be called when the event
-  // WebContentsObserver::DocumentOnLoadCompletedInMainFrame() occurs, so that
-  // concrete tasks can update their favicons.
+  // FaviconDriverObserver::OnFaviconUpdated() occurs, so that concrete tasks
+  // can update their favicons.
   virtual void UpdateFavicon() = 0;
 
   // task_management::Task:
   void Activate() override;
   void Refresh(const base::TimeDelta& update_interval,
                int64 refresh_flags) override;
   Type GetType() const override;
   int GetChildProcessUniqueID() const override;
   base::string16 GetProfileName() const override;
   int64 GetV8MemoryAllocated() const override;
   int64 GetV8MemoryUsed() const override;
   bool ReportsWebCacheStats() const override;
   blink::WebCache::ResourceTypeStats GetWebCacheStats() const override;
 
+  // favicon::FaviconDriverObserver:
+  void OnFaviconAvailable(const gfx::Image& image) override;
+  void OnFaviconUpdated(favicon::FaviconDriver* favicon_driver,
+                        bool icon_url_changed) override;
+
  protected:
   // Returns the title of the given |web_contents|.
   static base::string16 GetTitleFromWebContents(
       content::WebContents* web_contents);
 
   // Returns the favicon of the given |web_contents| if any, and returns
   // |nullptr| otherwise.
   static const gfx::ImageSkia* GetFaviconFromWebContents(
       content::WebContents* web_contents);
 
@@ skipping 33 matching lines @@
   // The profile name associated with the browser context of the render view
   // host.
   const base::string16 profile_name_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererTask);
 };
 
 }  // namespace task_management
 
 #endif  // CHROME_BROWSER_TASK_MANAGEMENT_PROVIDERS_WEB_CONTENTS_RENDERER_TASK_H_