DOM Storage: Add browser-process IPC code + tweak the WebKit Thread.

chrome/browser/in_process_webkit/webkit_thread.h

 // Copyright (c) 2009 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_IN_PROCESS_WEBKIT_WEBKIT_THREAD_H_
 #define CHROME_BROWSER_IN_PROCESS_WEBKIT_WEBKIT_THREAD_H_
 
 #include "base/lazy_instance.h"
 #include "base/lock.h"
 #include "base/logging.h"
@@ skipping 17 matching lines @@
   // Returns the message loop for the WebKit thread unless we're in
   // --single-processuntil mode, in which case it'll return NULL.  Only call
   // from the IO thread.  Only do fast-path work here.
   MessageLoop* GetMessageLoop() {
     DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
     if (!webkit_thread_.get())
       return InitializeThread();
     return webkit_thread_->message_loop();
   }
 
+  // Called from the IO thread.  Notifies us that it's no longer safe to post
+  // tasks to the IO thread.
+  void Shutdown();
+
+  // Post a task to the IO thread if we haven't yet been told to shut down.
+  // Only call from the WebKit thread.
+  bool PostIOThreadTask(const tracked_objects::Location& from_here,
+                        Task* task);
+
  private:
   // Must be private so that we can carefully control its lifetime.
   class InternalWebKitThread : public ChromeThread {
    public:
     InternalWebKitThread();
     virtual ~InternalWebKitThread() { }
     // Does the actual initialization and shutdown of WebKit.  Called at the
     // beginning and end of the thread's lifetime.
     virtual void Init();
     virtual void CleanUp();
 
    private:
     BrowserWebKitClientImpl* webkit_client_;
   };
 
   // Returns the WebKit thread's message loop or NULL if we're in
   // --single-process mode.  Do slow-path initialization work here.
   MessageLoop* InitializeThread();
 
   // Pointer to the actual WebKitThread.  NULL if not yet started.  Only modify
   // from the IO thread while the WebKit thread is not running.
   scoped_ptr<InternalWebKitThread> webkit_thread_;
 
+  // A pointer to the IO message loop.  This is nulled out when Shutdown() is
+  // called.  Only access under the io_message_loop_lock_.
+  MessageLoop* io_message_loop_;
+  Lock io_message_loop_lock_;
+
   DISALLOW_COPY_AND_ASSIGN(WebKitThread);
 };
 
 #endif  // CHROME_BROWSER_IN_PROCESS_WEBKIT_WEBKIT_THREAD_H_