Handle extension webrequest API on the IO thread. This speeds up blocking event

chrome/browser/extensions/extension_function_dispatcher.h

 // Copyright (c) 2011 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_FUNCTION_DISPATCHER_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_FUNCTION_DISPATCHER_H_
 #pragma once
 
 #include <string>
 #include <vector>
 
 #include "base/memory/weak_ptr.h"
+#include "chrome/browser/profiles/profile.h"
+#include "ipc/ipc_message.h"
 #include "googleurl/src/gurl.h"
 #include "ui/gfx/native_widget_types.h"
 
 class Browser;
+class ChromeRenderMessageFilter;
 class Extension;
 class ExtensionFunction;
 class ListValue;
 class Profile;
 class RenderViewHost;
 class TabContents;
 struct ExtensionHostMsg_Request_Params;
 
 // A factory function for creating new ExtensionFunction instances.
 typedef ExtensionFunction* (*ExtensionFunctionFactory)();
@@ skipping 38 matching lines @@
   static void GetAllFunctionNames(std::vector<std::string>* names);
 
   // Override a previously registered function. Returns true if successful,
   // false if no such function was registered.
   static bool OverrideFunction(const std::string& name,
                                ExtensionFunctionFactory factory);
 
   // Resets all functions to their initial implementation.
   static void ResetFunctions();
 
+  // Dispatches an IO-thread extension function. Only used for specific
+  // functions that must be handled on the IO-thread.
+  static void DispatchOnIOThread(
+      const ExtensionInfoMap* extension_info_map,
+      ProfileId profile_id,
+      int render_process_id,
+      base::WeakPtr<ChromeRenderMessageFilter> ipc_sender,
+      int routing_id,
+      const ExtensionHostMsg_Request_Params& params);
+
   // Public constructor. Callers must ensure that:
   // - |delegate| outlives this object.
   // - This object outlives any RenderViewHost's passed to created
   //   ExtensionFunctions.
   ExtensionFunctionDispatcher(Profile* profile, Delegate* delegate);
 
   ~ExtensionFunctionDispatcher();
 
   Delegate* delegate() { return delegate_; }
 
   // Message handlers.
   void Dispatch(const ExtensionHostMsg_Request_Params& params,
                 RenderViewHost* sender);
 
   // Returns the current browser. Callers should generally prefer
   // ExtensionFunction::GetCurrentBrowser() over this method, as that one
   // provides the correct value for |include_incognito|.
   //
   // See the comments for ExtensionFunction::GetCurrentBrowser() for more
   // details.
   Browser* GetCurrentBrowser(RenderViewHost* render_view_host,
                              bool include_incognito);
 
   // The profile that this dispatcher is associated with.
   Profile* profile() { return profile_; }
 
  private:
-  // Helper to send an access denied error to the requesting render view.
-  void SendAccessDenied(RenderViewHost* render_view_host, int request_id);
+  // Helper to creates an ExtensionFunction to handle the function given by

[battre, 2011/06/08 22:26:05]

nit: typo "Helper to creates"

+  // |params|. Can be called on any thread.
+  // Does not set subclass properties, or include_incognito.
+  static ExtensionFunction* CreateExtensionFunction(
+      const ExtensionHostMsg_Request_Params& params,
+      const Extension* extension,
+      ProfileId profile_id,
+      int render_process_id,
+      IPC::Message::Sender* ipc_sender,
+      int routing_id);
+
+  // Helper to send an access denied error to the requesting renderer. Can be
+  // called on any thread.
+  static void SendAccessDenied(IPC::Message::Sender* ipc_sender,
+                               int routing_id,
+                               int request_id);
 
   Profile* profile_;
 
   Delegate* delegate_;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_FUNCTION_DISPATCHER_H_