Make echo message per-command-buffer

content/common/gpu/gpu_messages.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.
 
 // Multiply-included message file, hence no include guard here, but see below
 // for a much smaller-than-usual include guard section.
 
 #include <vector>
 #include <string>
 
@@ skipping 280 matching lines @@
                             gfx::Size, /* size */
                             GPUCreateCommandBufferConfig, /* init_params */
                             int32 /* route_id */)
 
 // The CommandBufferProxy sends this to the GpuCommandBufferStub in its
 // destructor, so that the stub deletes the actual CommandBufferService
 // object that it's hosting.
 IPC_SYNC_MESSAGE_CONTROL1_0(GpuChannelMsg_DestroyCommandBuffer,
                             int32 /* instance_id */)
 
-// Request that the GPU process reply with the given message.
-IPC_MESSAGE_CONTROL1(GpuChannelMsg_Echo,
-                     IPC::Message /* reply */)
-
 // Asks the GPU process whether the creation or destruction of a
 // command buffer on the given GPU (integrated or discrete) will cause
 // the system to switch which GPU it is using. All contexts that share
 // resources need to be created on the same GPU.
 IPC_SYNC_MESSAGE_CONTROL2_1(GpuChannelMsg_WillGpuSwitchOccur,
                             bool /* is_creating_context */,
                             gfx::GpuPreference /* preference */,
                             bool /* will_cause_switch */)
 
 // Forcibly closes the channel on the GPU process side, in order to
@@ skipping 103 matching lines @@
 // browser. This message is currently used only on 10.6 and later.
 IPC_MESSAGE_ROUTED1(GpuCommandBufferMsg_SetWindowSize,
                     gfx::Size /* size */)
 #endif
 
 // Tells the proxy that there was an error and the command buffer had to be
 // destroyed for some reason.
 IPC_MESSAGE_ROUTED1(GpuCommandBufferMsg_Destroyed,
                     gpu::error::ContextLostReason /* reason */)
 
+// Request that the GPU process reply with the given message. Reply may be
+// delayed.
+IPC_MESSAGE_ROUTED1(GpuCommandBufferMsg_Echo,
+                    IPC::Message /* reply */)
+
 // Response to a GpuChannelMsg_Echo message.
 IPC_MESSAGE_ROUTED0(GpuCommandBufferMsg_EchoAck)
 
 // Send to stub on surface visibility change.
 IPC_MESSAGE_ROUTED1(GpuCommandBufferMsg_SetSurfaceVisible, bool /* visible */)
 
 // Sent to proxy when the gpu memory manager changes its memory allocation.
 IPC_MESSAGE_ROUTED1(GpuCommandBufferMsg_SetMemoryAllocation,
                     GpuMemoryAllocation /* allocation */)
 
@@ skipping 55 matching lines @@
 
 // Confirm decoder has been flushed.
 IPC_MESSAGE_ROUTED0(AcceleratedVideoDecoderHostMsg_FlushDone)
 
 // Confirm decoder has been reset.
 IPC_MESSAGE_ROUTED0(AcceleratedVideoDecoderHostMsg_ResetDone)
 
 // Video decoder has encountered an error.
 IPC_MESSAGE_ROUTED1(AcceleratedVideoDecoderHostMsg_ErrorNotification,
                     uint32) /* Error ID */