Task Manager: Make double-clicking on an extension do something useful.

chrome/browser/task_management/providers/web_contents/subframe_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_SUBFRAME_TASK_H_
 #define CHROME_BROWSER_TASK_MANAGEMENT_PROVIDERS_WEB_CONTENTS_SUBFRAME_TASK_H_
 
 #include "base/macros.h"
 #include "chrome/browser/task_management/providers/web_contents/renderer_task.h"
 
 namespace content {
 class RenderFrameHost;
 class WebContents;
 }  // namespace content
 
 namespace task_management {
 
 // Defines a concrete renderer task that can represent processes hosting
 // out-of-process iframes.
 class SubframeTask : public RendererTask {
  public:
   SubframeTask(content::RenderFrameHost* render_frame_host,
-               content::WebContents* web_contents);
+               content::WebContents* web_contents,
+               RendererTask* main_task);
   ~SubframeTask() override;
 
   // task_management::RendererTask:
   void UpdateTitle() override;
   void UpdateFavicon() override;
+  void Activate() override;
 
  private:
+  // The task for the main frame of this WebContents.
+  RendererTask* main_task_;
   DISALLOW_COPY_AND_ASSIGN(SubframeTask);
 };
 
 }  // namespace task_management
 
 
 #endif  // CHROME_BROWSER_TASK_MANAGEMENT_PROVIDERS_WEB_CONTENTS_SUBFRAME_TASK_H_