Introduce runtime.onSuspendCanceled() event.

chrome/browser/extensions/extension_process_manager.h

 // 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_PROCESS_MANAGER_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_PROCESS_MANAGER_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 95 matching lines @@
       content::RenderViewHost* render_view_host);
 
   // Returns true if the (lazy) background host for the given extension has
   // already been sent the unload event and is shutting down.
   bool IsBackgroundHostClosing(const std::string& extension_id);
 
   // Getter and setter for the lazy background page's keepalive count. This is
   // the count of how many outstanding "things" are keeping the page alive.
   // When this reaches 0, we will begin the process of shutting down the page.
   // "Things" include pending events, resource loads, and API calls.
+  // The |cancel_suspend| option defaults to false and indicates whether

[benwells, 2012/07/20 10:57:00]

I'd prefer |cancel_suspend| to be a non-optional enum.

Enum makes call sites easier to understand. Making this parameter optional is in
effect creating a default parameter value, which is against the google c++ style
guide.

+  // incrementing the keepalive count should prevent it from being suspended.
   int GetLazyKeepaliveCount(const extensions::Extension* extension);
   int IncrementLazyKeepaliveCount(const extensions::Extension* extension);
+  int IncrementLazyKeepaliveCount(const extensions::Extension* extension,
+                                  bool cancel_suspend);
   int DecrementLazyKeepaliveCount(const extensions::Extension* extension);
 
   void IncrementLazyKeepaliveCountForView(
       content::RenderViewHost* render_view_host);
 
   // Handles a response to the ShouldUnload message, used for lazy background
   // pages.
   void OnShouldUnloadAck(const std::string& extension_id, int sequence_id);
 
   // Same as above, for the Unload message.
@@ skipping 50 matching lines @@
 
   // Ensure browser object is not null except for certain situations.
   void EnsureBrowserWhenRequired(Browser* browser,
                                  chrome::ViewType view_type);
 
   // These are called when the extension transitions between idle and active.
   // They control the process of closing the background page when idle.
   void OnLazyBackgroundPageIdle(const std::string& extension_id,
                                 int sequence_id);
   void OnLazyBackgroundPageActive(const std::string& extension_id);
-  void CloseLazyBackgroundPageNow(const std::string& extension_id);
+  void CloseLazyBackgroundPageNow(const std::string& extension_id,
+                                  int sequence_id);
 
   // Updates a potentially-registered RenderViewHost once it has been
   // associated with a WebContents. This allows us to gather information that
   // was not available when the host was first registered.
   void UpdateRegisteredRenderView(content::RenderViewHost* render_view_host);
 
   // Clears background page data for this extension.
   void ClearBackgroundPageData(const std::string& extension_id);
 
   BackgroundPageDataMap background_page_data_;
 
   // The time to delay between an extension becoming idle and
   // sending a ShouldUnload message; read from command-line switch.
   base::TimeDelta event_page_idle_time_;
 
   // The time to delay between sending a ShouldUnload message and
   // sending a Unload message; read from command-line switch.
   base::TimeDelta event_page_unloading_time_;
 
   base::WeakPtrFactory<ExtensionProcessManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionProcessManager);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_PROCESS_MANAGER_H_