Make gpu black list work again on Linux

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 <stdint.h>
 
 #include <string>
@@ skipping 411 matching lines @@
 
 // A renderer sends this when it wants to create a connection to the GPU
 // process. The browser will create the GPU process if necessary, and will
 // return a handle to the channel via a GpuChannelEstablished message.
 IPC_SYNC_MESSAGE_CONTROL1_3(GpuHostMsg_EstablishGpuChannel,
                             content::CauseForGpuLaunch,
                             int /* client id */,
                             IPC::ChannelHandle /* handle to channel */,
                             gpu::GPUInfo /* stats about GPU process*/)
 
+// A renderer sends this when it wants to know whether a gpu process exists.
+IPC_SYNC_MESSAGE_CONTROL0_1(GpuHostMsg_HasGpuProcess, bool /* result */)
+
 // Response from GPU to a GputMsg_Initialize message.
 IPC_MESSAGE_CONTROL2(GpuHostMsg_Initialized,
                      bool /* result */,
                      ::gpu::GPUInfo /* gpu_info */)
 
 // Response from GPU to a GpuHostMsg_EstablishChannel message.
 IPC_MESSAGE_CONTROL1(GpuHostMsg_ChannelEstablished,
                      IPC::ChannelHandle /* channel_handle */)
 
 // Message from GPU to notify to destroy the channel.
@@ skipping 384 matching lines @@
 IPC_MESSAGE_ROUTED0(AcceleratedJpegDecoderMsg_Destroy)
 
 //------------------------------------------------------------------------------
 // Accelerated JPEG Decoder Host Messages
 // These messages are sent from the GPU process to Browser process.
 //
 // Report decode status.
 IPC_MESSAGE_ROUTED2(AcceleratedJpegDecoderHostMsg_DecodeAck,
                     int32_t, /* bitstream_buffer_id */
                     media::JpegDecodeAccelerator::Error /* error */)