Impl mus::mojom::GpuService to enable using Chrome IPC version gpu CmdBuf in mus

components/mus/public/cpp/lib/gpu_service.cc

Index: components/mus/public/cpp/lib/gpu_service.cc
diff --git a/components/mus/public/cpp/lib/gpu_service.cc b/components/mus/public/cpp/lib/gpu_service.cc
new file mode 100644
index 0000000000000000000000000000000000000000..7e7c253046b5189e6457c21da409173dca3436ee
--- /dev/null
+++ b/components/mus/public/cpp/lib/gpu_service.cc
@@ -0,0 +1,101 @@
+// Copyright 2016 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 "components/mus/public/cpp/lib/gpu_service.h"
+
+#include "base/command_line.h"
+#include "base/memory/singleton.h"
+#include "components/mus/common/gpu_type_converters.h"
+#include "components/mus/common/switches.h"
+#include "components/mus/public/cpp/lib/gpu_memory_buffer_manager_mus.h"
+#include "components/mus/public/interfaces/gpu_service.mojom.h"
+#include "services/shell/public/cpp/connector.h"
+
+namespace mus {
+
+namespace {
+
+void GpuChannelEstablishCallback(int* client_id_out,
+                                 IPC::ChannelHandle* channel_handle_out,
+                                 gpu::GPUInfo* gpu_info_out,
+                                 int client_id,
+                                 mus::mojom::ChannelHandlePtr channel_handle,
+                                 mus::mojom::GpuInfoPtr gpu_info) {
+  *client_id_out = client_id;
+  *channel_handle_out = channel_handle.To<IPC::ChannelHandle>();
+  // TODO(penghuang): Get the gpu info.
+}
+}
+
+GpuService::GpuService()
+    : main_message_loop_(base::MessageLoop::current()),
+      shutdown_event_(false, false),
+      io_thread_("GPUIOThread"),
+      gpu_memory_buffer_manager_(new mus::GpuMemoryBufferManagerMus) {
+  base::Thread::Options thread_options(base::MessageLoop::TYPE_IO, 0);
+  thread_options.priority = base::ThreadPriority::NORMAL;
+  CHECK(io_thread_.StartWithOptions(thread_options));
+}
+
+GpuService::~GpuService() {}
+
+// static
+bool GpuService::UseChromeGpuCommandBuffer() {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kUseChromeGpuCommandBufferInMus);
+}
+
+// static
+GpuService* GpuService::GetInstance() {
+  return base::Singleton<GpuService,
+                         base::LeakySingletonTraits<GpuService>>::get();
+}
+
+scoped_refptr<gpu::GpuChannelHost> GpuService::EstablishGpuChannel(
+    shell::Connector* connector) {
+  if (gpu_channel_ && gpu_channel_->IsLost()) {
+    gpu_channel_->DestroyChannel();
+    gpu_channel_ = nullptr;
+  }
+
+  if (gpu_channel_)
+    return gpu_channel_;
+
+  mus::mojom::GpuServicePtr gpu_service;
+  connector->ConnectToInterface("mojo:mus", &gpu_service);
+
+  int client_id = 0;
+  IPC::ChannelHandle channel_handle;
+  gpu::GPUInfo gpu_info;
+  gpu_service->EstablishGpuChannel(base::Bind(
+      &GpuChannelEstablishCallback, &client_id, &channel_handle, &gpu_info));
+  if (!gpu_service.WaitForIncomingResponse()) {
+    DLOG(WARNING)
+        << "Channel encountered error while establishing gpu channel.";
+    return nullptr;
+  }
+  gpu_channel_ = gpu::GpuChannelHost::Create(this, client_id, gpu_info,
+                                             channel_handle, &shutdown_event_,
+                                             gpu_memory_buffer_manager_.get());
+  return gpu_channel_;
+}
+
+bool GpuService::IsMainThread() {
+  return base::MessageLoop::current() == main_message_loop_;
+}
+
+scoped_refptr<base::SingleThreadTaskRunner>
+GpuService::GetIOThreadTaskRunner() {
+  return io_thread_.task_runner();
+}
+
+std::unique_ptr<base::SharedMemory> GpuService::AllocateSharedMemory(
+    size_t size) {
+  std::unique_ptr<base::SharedMemory> shm(new base::SharedMemory());
+  if (!shm->CreateAnonymous(size))
+    return std::unique_ptr<base::SharedMemory>();
+  return shm;
+}
+
+}  // namespace mus