Handful of changes to get mus to shutdown correctly

components/mus/gles2/gpu_state.h

 // Copyright 2015 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 COMPONENTS_MUS_GLES2_GPU_STATE_H_
 #define COMPONENTS_MUS_GLES2_GPU_STATE_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 15 matching lines @@
 // We need to share these across all CommandBuffer instances so that contexts
 // they create can share resources with each other via mailboxes.
 class GpuState : public base::RefCountedThreadSafe<GpuState> {
  public:
   GpuState();
 
   // We run the CommandBufferImpl on the control_task_runner, which forwards
   // most method class to the CommandBufferDriver, which runs on the "driver",
   // thread (i.e., the thread on which GpuImpl instances are created).
   scoped_refptr<base::SingleThreadTaskRunner> control_task_runner() {
-    return control_thread_.task_runner();
+    return control_thread_task_runner_;
   }
 
   void StopThreads();
 
   const gpu::GpuPreferences& gpu_preferences() const {
     return gpu_preferences_;
   }
 
   CommandBufferTaskRunner* command_buffer_task_runner() const {
     return command_buffer_task_runner_.get();
@@ skipping 20 matching lines @@
   bool HardwareRenderingAvailable() const {
     return hardware_rendering_available_;
   }
 
  private:
   friend class base::RefCountedThreadSafe<GpuState>;
   ~GpuState();
 
   void InitializeOnGpuThread(base::WaitableEvent* event);
 
+  void DestroyGpuSpecificStateOnGpuThread();
+
   // |gpu_thread_| is for executing OS GL calls.
   base::Thread gpu_thread_;
   // |control_thread_| is for mojo incoming calls of CommandBufferImpl.
   base::Thread control_thread_;
 
+  // Same as control_thread_->task_runner(). The TaskRunner is cached as it may
+  // be needed during shutdown.
+  scoped_refptr<base::SingleThreadTaskRunner> control_thread_task_runner_;
+
   gpu::GpuPreferences gpu_preferences_;
   scoped_refptr<CommandBufferTaskRunner> command_buffer_task_runner_;
   scoped_ptr<CommandBufferDriverManager> driver_manager_;
   scoped_ptr<gpu::SyncPointManager> sync_point_manager_;
   scoped_refptr<gfx::GLShareGroup> share_group_;
   scoped_refptr<gpu::gles2::MailboxManager> mailbox_manager_;
   gpu::GPUInfo gpu_info_;
   bool hardware_rendering_available_;
 };
 
 }  // namespace mus
 
 #endif  // COMPONENTS_MUS_GLES2_GPU_STATE_H_