Added a unique command buffer ID for command buffers.

gpu/command_buffer/service/in_process_command_buffer.h

Index: gpu/command_buffer/service/in_process_command_buffer.h
diff --git a/gpu/command_buffer/service/in_process_command_buffer.h b/gpu/command_buffer/service/in_process_command_buffer.h
index b06a442555d465b947b6f32072495c9804830772..b9309739b574e090a276ad2f9d3c9fc10860042a 100644
--- a/gpu/command_buffer/service/in_process_command_buffer.h
+++ b/gpu/command_buffer/service/in_process_command_buffer.h
@@ -126,6 +126,8 @@ class GPU_EXPORT InProcessCommandBuffer : public CommandBuffer,
   uint32 CreateStreamTexture(uint32 texture_id) override;
   void SetLock(base::Lock*) override;
   bool IsGpuChannelLost() override;
+  CommandBufferNamespace GetNamespaceID() const override;
+  uint64_t GetCommandBufferID() const override;
 
   // The serializer interface to the GPU service (i.e. thread).
   class Service {
@@ -228,6 +230,8 @@ class GPU_EXPORT InProcessCommandBuffer : public CommandBuffer,
   void PumpCommands();
   void PerformIdleWork();
 
+  const uint64_t command_buffer_id_;
+
   // Members accessed on the gpu thread (possibly with the exception of
   // creation):
   bool context_lost_;