Fix bug where transient pages would miss events dispatched while it was

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_
 #pragma once
 
 #include <map>
 #include <set>
@@ skipping 71 matching lines @@
   void UnregisterRenderViewHost(content::RenderViewHost* render_view_host);
 
   // Returns all RenderViewHosts that are registered for the specified
   // extension.
   std::set<content::RenderViewHost*> GetRenderViewHostsForExtension(
       const std::string& extension_id);
 
   // Returns true if |host| is managed by this process manager.
   bool HasExtensionHost(ExtensionHost* host) const;
 
+  // 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.
   int GetLazyKeepaliveCount(const Extension* extension);
   int IncrementLazyKeepaliveCount(const Extension* extension);
   int DecrementLazyKeepaliveCount(const Extension* extension);
 
   // Handles a response to the ShouldUnload message, used for lazy background
   // pages.
@@ skipping 72 matching lines @@
   // 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);
 
   BackgroundPageDataMap background_page_data_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionProcessManager);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_PROCESS_MANAGER_H_