Revert changes to GPU test MessageLoop type.

gpu/ipc/service/gpu_channel_unittest.cc

 // Copyright (c) 2015 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.
 
 #include <stdint.h>
 
 #include "base/memory/shared_memory.h"
 #include "base/test/test_message_loop.h"
 #include "gpu/ipc/common/gpu_messages.h"
 #include "gpu/ipc/service/gpu_channel.h"
 #include "gpu/ipc/service/gpu_channel_manager.h"
 #include "gpu/ipc/service/gpu_channel_test_common.h"
-#include "gpu/test_message_loop_type.h"
 #include "ipc/ipc_test_sink.h"
 #include "ui/gl/gl_surface_stub.h"
 #include "ui/gl/init/gl_factory.h"
 #include "ui/gl/test/gl_surface_test_support.h"
 
 namespace gpu {
 
 class GpuChannelTest : public GpuChannelTestCommon {
  public:
-  GpuChannelTest()
-      : GpuChannelTestCommon(),
-        message_loop_(test::GetMessageLoopTypeForGpu()) {}
+  GpuChannelTest() : GpuChannelTestCommon() {}
   ~GpuChannelTest() override {}
 
   void SetUp() override {
     // We need GL bindings to actually initialize command buffers.
     gl::GLSurfaceTestSupport::InitializeOneOffWithStubBindings();
 
     GpuChannelTestCommon::SetUp();
   }
 
   void TearDown() override {
@@ skipping 365 matching lines @@
   EXPECT_TRUE(channel->LookupCommandBuffer(kSharedRouteId));
 
   // Destroy the command buffers we initialized before destoying GL.
   HandleMessage(channel,
                 new GpuChannelMsg_DestroyCommandBuffer(kFriendlyRouteId));
   HandleMessage(channel,
                 new GpuChannelMsg_DestroyCommandBuffer(kSharedRouteId));
 }
 
 }  // namespace gpu