Clarify ownership of GpuVideoDecodeAcceleratorHost and avoid crash on context loss.

content/common/gpu/client/command_buffer_proxy_impl.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_COMMON_GPU_CLIENT_COMMAND_BUFFER_PROXY_IMPL_H_
 #define CONTENT_COMMON_GPU_CLIENT_COMMAND_BUFFER_PROXY_IMPL_H_
 
 #if defined(ENABLE_GPU)
 
 #include <map>
@@ skipping 89 matching lines @@
   // TODO(apatrick): this is a temporary optimization while skia is calling
   // ContentGLContext::MakeCurrent prior to every GL call. It saves returning 6
   // ints redundantly when only the error is needed for the
   // CommandBufferProxyImpl implementation.
   virtual gpu::error::Error GetLastError() OVERRIDE;
 
   GpuChannelHost* channel() const { return channel_; }
 
  private:
   typedef std::map<int32, gpu::Buffer> TransferBufferMap;
-  typedef std::map<int, GpuVideoDecodeAcceleratorHost*> Decoders;
+  typedef std::map<int, base::WeakPtr<GpuVideoDecodeAcceleratorHost> > Decoders;
   typedef base::hash_map<uint32, base::Closure> SignalTaskMap;
 
   // Send an IPC message over the GPU channel. This is private to fully
   // encapsulate the channel; all callers of this function must explicitly
   // verify that the context has not been lost.
   bool Send(IPC::Message* msg);
 
   // Message handlers:
   void OnUpdateState(const gpu::CommandBuffer::State& state);
   void OnNotifyRepaint();
   void OnDestroyed(gpu::error::ContextLostReason reason);
   void OnEchoAck();
   void OnConsoleMessage(const GPUCommandBufferConsoleMessage& message);
   void OnSetMemoryAllocation(const GpuMemoryAllocationForRenderer& allocation);
   void OnSignalSyncPointAck(uint32 id);
 
   // Try to read an updated copy of the state from shared memory.
   void TryUpdateState();
 
   // Local cache of id to transfer buffer mapping.
   TransferBufferMap transfer_buffers_;
 
-  // Zero or more video decoder hosts owned by this proxy, keyed by their
-  // decoder_route_id.
+  // Zero or more (unowned!) video decoder hosts using this proxy, keyed by
+  // their decoder_route_id.
   Decoders video_decoder_hosts_;
 
   // The last cached state received from the service.
   State last_state_;
 
   // The shared memory area used to update state.
   gpu::CommandBufferSharedState* shared_state_;
 
   // |*this| is owned by |*channel_| and so is always outlived by it, so using a
   // raw pointer is ok.
@@ skipping 17 matching lines @@
   // Tasks to be invoked in SignalSyncPoint responses.
   uint32 next_signal_id_;
   SignalTaskMap signal_tasks_;
 
   DISALLOW_COPY_AND_ASSIGN(CommandBufferProxyImpl);
 };
 
 #endif  // ENABLE_GPU
 
 #endif  // CONTENT_COMMON_GPU_CLIENT_COMMAND_BUFFER_PROXY_IMPL_H_