Fix potential shutdown deadlock in UI service

services/ui/public/cpp/gpu/client_gpu_memory_buffer_manager.h

Index: services/ui/public/cpp/gpu/client_gpu_memory_buffer_manager.h
diff --git a/services/ui/public/cpp/gpu/client_gpu_memory_buffer_manager.h b/services/ui/public/cpp/gpu/client_gpu_memory_buffer_manager.h
index 26d78ea5781ceb1ffc894cfd8784a668392ef2df..b42783d2f44daf44f7c434d5836e56e6a6a24f4c 100644
--- a/services/ui/public/cpp/gpu/client_gpu_memory_buffer_manager.h
+++ b/services/ui/public/cpp/gpu/client_gpu_memory_buffer_manager.h
@@ -6,6 +6,7 @@
 #define SERVICES_UI_PUBLIC_CPP_GPU_CLIENT_GPU_MEMORY_BUFFER_MANAGER_H_
 
 #include <memory>
+#include <set>
 #include <vector>
 
 #include "base/macros.h"
@@ -45,11 +46,19 @@ class ClientGpuMemoryBufferManager : public gpu::GpuMemoryBufferManager {
       gpu::SurfaceHandle surface_handle) override;
   void SetDestructionSyncToken(gfx::GpuMemoryBuffer* buffer,
                                const gpu::SyncToken& sync_token) override;
+
+  void DisconnectGpuOnThread();
+  void OnGpuMemoryBufferAllocatedOnThread(

[sadrul, 2017/01/21 02:54:31]

Move these above to group with
TearDownThread()/AllocateGpuMemoryBufferOnThread()?

[Ken Rockot(use gerrit already), 2017/01/23 18:00:50]

Done

+      gfx::GpuMemoryBufferHandle* ret_handle,
+      base::WaitableEvent* wait,
+      const gfx::GpuMemoryBufferHandle& handle);
+
   int counter_ = 0;
   // TODO(sad): Explore the option of doing this from an existing thread.
   base::Thread thread_;
   mojom::GpuPtr gpu_;
   base::WeakPtr<ClientGpuMemoryBufferManager> weak_ptr_;
+  std::set<base::WaitableEvent*> pending_allocation_waiters_;
   base::WeakPtrFactory<ClientGpuMemoryBufferManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ClientGpuMemoryBufferManager);