Make ChildThread::current() and ChildProcess::current() only work on the main thread of the child...

content/child/child_process.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 CONTENT_CHILD_CHILD_PROCESS_H_
 #define CONTENT_CHILD_CHILD_PROCESS_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/waitable_event.h"
@@ skipping 35 matching lines @@
   // webkit_glue::GetCookies.
   base::WaitableEvent* GetShutDownEvent();
 
   // These are used for ref-counting the child process.  The process shuts
   // itself down when the ref count reaches 0.
   // For example, in the renderer process, generally each tab managed by this
   // process will hold a reference to the process, and release when closed.
   void AddRefProcess();
   void ReleaseProcess();
 
-  // Getter for the one ChildProcess object for this process.
+  // Getter for the one ChildProcess object for this process. Can only be called
+  // on the main thread.
   static ChildProcess* current();
 
   static void WaitForDebugger(const std::string& label);
  private:
   int ref_count_;
 
   // An event that will be signalled when we shutdown.
   base::WaitableEvent shutdown_event_;
 
   // The thread that handles IO events.
   base::Thread io_thread_;
 
   // NOTE: make sure that main_thread_ is listed after shutdown_event_, since
   // it depends on it (indirectly through IPC::SyncChannel).  Same for
   // io_thread_.
   scoped_ptr<ChildThread> main_thread_;
 
   DISALLOW_COPY_AND_ASSIGN(ChildProcess);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_CHILD_PROCESS_H_