Change the lifetime of the WebKit thread to be a subset of the IO thread's li...

chrome/browser/chrome_thread.h

 // Copyright (c) 2006-2008 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_CHROME_THREAD_H__
 #define CHROME_BROWSER_CHROME_THREAD_H__
 
 #include "base/lock.h"
 #include "base/thread.h"
 
@@ skipping 20 matching lines @@
   enum ID {
     // This is the thread that processes IPC and network messages.
     IO,
 
     // This is the thread that interacts with the file system.
     FILE,
 
     // This is the thread that interacts with the database.
     DB,
 
+    // This is the "main" thread for WebKit within the browser process when
+    // NOT in --single-process mode.
+    WEBKIT,
+
     // This is the thread that interacts with the history database.
     HISTORY,
 
 #if defined(OS_LINUX)
     // This thread has a second connection to the X server and is used to
     // process UI requests when routing the request to the UI thread would risk
     // deadlock.
     BACKGROUND_X11,
 #endif
 
@@ skipping 10 matching lines @@
 
   // Callable on any thread, this helper function returns a pointer to the
   // thread's MessageLoop.
   //
   // WARNING:
   //   Nothing in this class prevents the MessageLoop object returned from this
   //   function from being destroyed on another thread.  Use with care.
   //
   static MessageLoop* GetMessageLoop(ID identifier);
 
+  // Callable on any thread.  Returns whether you're currently on a particular
+  // thread.
+  //
+  // WARNING:
+  //   When running under unit-tests, this will return true if you're on the
+  //   main thread and the thread ID you pass in isn't running.  This is
+  //   normally the correct behavior because you want to ignore these asserts
+  //   unless you've specifically spun up the threads, but be mindful of it.
+  static bool CurrentlyOn(ID identifier);
+
  private:
   // The identifier of this thread.  Only one thread can exist with a given
   // identifier at a given time.
   ID identifier_;
 
   // This lock protects |chrome_threads_|.  Do not read or modify that array
   // without holding this lock.  Do not block while holding this lock.
   static Lock lock_;
 
   // An array of the ChromeThread objects.  This array is protected by |lock_|.
   // The threads are not owned by this array.  Typically, the threads are owned
   // on the UI thread by the g_browser_process object.  ChromeThreads remove
   // themselves from this array upon destruction.
   static ChromeThread* chrome_threads_[ID_COUNT];
 };
 
 #endif  // #ifndef CHROME_BROWSER_CHROME_THREAD_H__