Re-land alexbost's experimental Offscreen Tabs API work.

chrome/browser/extensions/extension_tabs_module.h

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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_EXTENSIONS_EXTENSION_TABS_MODULE_H__
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_TABS_MODULE_H__
 #pragma once
 
 #include <string>
 #include <vector>
 
@@ skipping 90 matching lines @@
 };
 class HighlightTabsFunction : public SyncExtensionFunction {
   virtual ~HighlightTabsFunction() {}
   virtual bool RunImpl() OVERRIDE;
   DECLARE_EXTENSION_FUNCTION_NAME("tabs.highlight")
 };
 class UpdateTabFunction : public AsyncExtensionFunction,
                           public content::WebContentsObserver {
  public:
   UpdateTabFunction();
+ protected:
+  virtual ~UpdateTabFunction() {}
  private:
-  virtual ~UpdateTabFunction() {}
   virtual bool RunImpl() OVERRIDE;
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
   void OnExecuteCodeFinished(int request_id,
                              bool success,
                              const std::string& error);
   DECLARE_EXTENSION_FUNCTION_NAME("tabs.update")
 };
 class MoveTabsFunction : public SyncExtensionFunction {
   virtual ~MoveTabsFunction() {}
   virtual bool RunImpl() OVERRIDE;
@@ skipping 17 matching lines @@
 
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
   void GotLanguage(const std::string& language);
   content::NotificationRegistrar registrar_;
   DECLARE_EXTENSION_FUNCTION_NAME("tabs.detectLanguage")
 };
 class CaptureVisibleTabFunction : public AsyncExtensionFunction,
                                   public content::NotificationObserver {
- private:
+ protected:
   enum ImageFormat {
     FORMAT_JPEG,
     FORMAT_PNG
   };
 
   // The default quality setting used when encoding jpegs.
   static const int kDefaultQuality;
 
   virtual ~CaptureVisibleTabFunction() {}
   virtual bool RunImpl() OVERRIDE;
   virtual bool CaptureSnapshotFromBackingStore(BackingStore* backing_store);
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
   virtual void SendResultFromBitmap(const SkBitmap& screen_capture);
 
   content::NotificationRegistrar registrar_;
 
   // The format (JPEG vs PNG) of the resulting image.  Set in RunImpl().
   ImageFormat image_format_;
 
   // Quality setting to use when encoding jpegs.  Set in RunImpl().
   int image_quality_;
 
   DECLARE_EXTENSION_FUNCTION_NAME("tabs.captureVisibleTab")
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_TABS_MODULE_H__