Introduce runtime.onSuspendCanceled() event.

chrome/browser/extensions/extension_process_manager.h

Index: chrome/browser/extensions/extension_process_manager.h
diff --git a/chrome/browser/extensions/extension_process_manager.h b/chrome/browser/extensions/extension_process_manager.h
index eea12952a7f17e03f172bddf37a65fbe880fdebb..68609e3cc9f7a569ca4cf83f4d1c12a7940521e1 100644
--- a/chrome/browser/extensions/extension_process_manager.h
+++ b/chrome/browser/extensions/extension_process_manager.h
@@ -113,8 +113,12 @@ class ExtensionProcessManager : public content::NotificationObserver {
   // 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
+  // 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(
@@ -132,6 +136,9 @@ class ExtensionProcessManager : public content::NotificationObserver {
   void OnNetworkRequestStarted(content::RenderViewHost* render_view_host);
   void OnNetworkRequestDone(content::RenderViewHost* render_view_host);
 
+  // Prevent the specified extension from being suspended.
+  void CancelSuspend(const std::string& extension_id);
+
  protected:
   explicit ExtensionProcessManager(Profile* profile);
 
@@ -185,7 +192,9 @@ class ExtensionProcessManager : public content::NotificationObserver {
   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 MaybePostOnLazyBackgroundPageIdle(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