Remove all but one use of WeakPtrFactory::DetachFromThread.

ui/gl/gl_surface_glx.cc

 // 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.
 
 extern "C" {
 #include <X11/Xlib.h>
 }
 
 #include "ui/gl/gl_surface_glx.h"
 
@@ skipping 222 matching lines @@
 
 class SGIVideoSyncVSyncProvider
     : public gfx::VSyncProvider,
       public base::SupportsWeakPtr<SGIVideoSyncVSyncProvider> {
  public:
   explicit SGIVideoSyncVSyncProvider(gfx::AcceleratedWidget window)
       : vsync_thread_(SGIVideoSyncThread::Create()),
         shim_((new SGIVideoSyncProviderThreadShim(window))->AsWeakPtr()),
         cancel_vsync_flag_(shim_->cancel_vsync_flag()),
         vsync_lock_(shim_->vsync_lock()) {
-    // The WeakPtr is bound to the SGIVideoSyncThread. We only use it for
-    // PostTask.
-    shim_->DetachFromThread();
     vsync_thread_->message_loop()->PostTask(
         FROM_HERE,
         base::Bind(&SGIVideoSyncProviderThreadShim::Initialize, shim_));
   }
 
   virtual ~SGIVideoSyncVSyncProvider() {
     {
       base::AutoLock locked(*vsync_lock_);
       cancel_vsync_flag_->Set();
     }
@@ skipping 359 matching lines @@
 
 void* PbufferGLSurfaceGLX::GetConfig() {
   return config_;
 }
 
 PbufferGLSurfaceGLX::~PbufferGLSurfaceGLX() {
   Destroy();
 }
 
 }  // namespace gfx