Fixed null dereference in GPU watchdog termination code....

chrome/gpu/gpu_thread.cc

 // Copyright (c) 2010 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.
 
 #include "chrome/gpu/gpu_thread.h"
 
 #include <string>
 #include <vector>
 
 #include "app/gfx/gl/gl_context.h"
@@ skipping 111 matching lines @@
 }
 #endif
 
 void GpuThread::OnCrash() {
   // Good bye, cruel world.
   volatile int* it_s_the_end_of_the_world_as_we_know_it = NULL;
   *it_s_the_end_of_the_world_as_we_know_it = 0xdead;
 }
 
 void GpuThread::OnHang() {
-  for (;;)
-    PlatformThread::Sleep(1000);
+  for (;;) {
+    // Do not sleep here. The GPU watchdog timer tracks the amount of user
+    // time this thread is using and it doesn't use much while calling Sleep.
+  }
 }
 
 #if defined(OS_WIN)
 
 // Runs on a worker thread. The GpuThread never terminates voluntarily so it is
 // safe to assume that its message loop is valid.
 void GpuThread::CollectDxDiagnostics(GpuThread* thread) {
   win_util::ScopedCOMInitializer com_initializer;
 
   DxDiagNode node;
   gpu_info_collector::GetDxDiagnostics(&node);
 
   thread->message_loop()->PostTask(
       FROM_HERE,
       NewRunnableFunction(&GpuThread::SetDxDiagnostics, thread, node));
 }
 
 // Runs on the GPU thread.
 void GpuThread::SetDxDiagnostics(GpuThread* thread, const DxDiagNode& node) {
   thread->gpu_info_.SetDxDiagnostics(node);
   thread->gpu_info_.SetProgress(GPUInfo::kComplete);
 }
 
 #endif