Implement GpuArcVideoService for arc video accelerator

content/browser/gpu/gpu_arc_video_service_host.cc

+// Copyright 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 "content/browser/gpu/gpu_arc_video_service_host.h"
+
+#include "base/location.h"
+#include "base/logging.h"
+#include "base/message_loop/message_loop.h"
+#include "content/browser/gpu/gpu_process_host.h"
+#include "content/common/gpu/gpu_messages.h"
+#include "content/public/browser/arc_video_host_delegate.h"
+#include "content/public/browser/browser_thread.h"
+#include "ipc/ipc_channel_handle.h"
+#include "ipc/ipc_message_macros.h"
+#include "ipc/ipc_message_utils.h"
+#include "third_party/mojo/src/mojo/edk/embedder/embedder.h"
+
+namespace content {
+
+namespace {
+void CreateChannelOnIOThread(
+    const GpuProcessHost::CreateArcVideoAcceleratorChannelCallback& callback) {
+  GpuProcessHost* gpu_process_host =
+      GpuProcessHost::Get(GpuProcessHost::GPU_PROCESS_KIND_SANDBOXED,
+                          CAUSE_FOR_GPU_LAUNCH_ARCVIDEOACCELERATOR);
+  gpu_process_host->CreateArcVideoAcceleratorChannel(callback);
+}
+}
+
+scoped_ptr<arc::VideoHostDelegate> CreateArcVideoHostDelegate() {
+  return make_scoped_ptr(new GpuArcVideoServiceHost());
+}
+
+GpuArcVideoServiceHost::GpuArcVideoServiceHost()
+    : io_task_runner_(content::BrowserThread::GetMessageLoopProxyForThread(
+          content::BrowserThread::IO)),
+      weak_factory_(this) {}
+
+GpuArcVideoServiceHost::~GpuArcVideoServiceHost() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void GpuArcVideoServiceHost::OnRequestArcVideoAcceleratorChannel(
+    const OnRequestArcVideoAcceleratorChannelCallback& callback) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  io_task_runner_->PostTask(

[jbauman, 2015/12/30 01:29:29]

What threads can this be called on? HandleChannelCreatedReply will be called on
the IO thread by the GPUProcessHost, so it seems like this must be called on
that thread as well, and this PostTask should be unnecessary.

[kcwu, 2015/12/30 09:40:33]

Ah, HandleChannelCreatedReply is called on the IO thread and my DCHECK was
wrong. I revised it.

Regarding threads, GpuProcessHost::Get() must be called on IO thread, so
PostTask to IO thread is necessary.

+      FROM_HERE,
+      base::Bind(&CreateChannelOnIOThread,
+                 base::Bind(&GpuArcVideoServiceHost::HandleChannelCreatedReply,
+                            weak_factory_.GetWeakPtr(), callback)));
+}
+
+void GpuArcVideoServiceHost::Shutdown() {
+  GpuProcessHost::SendOnIO(GpuProcessHost::GPU_PROCESS_KIND_SANDBOXED,
+                           CAUSE_FOR_GPU_LAUNCH_NO_LAUNCH,
+                           new GpuMsg_ShutdownArcVideoService());
+}
+
+void GpuArcVideoServiceHost::HandleChannelCreatedReply(
+    const OnRequestArcVideoAcceleratorChannelCallback& callback,
+    const IPC::ChannelHandle& handle) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  MojoHandle wrapped_handle;
+  MojoResult wrap_result = mojo::embedder::CreatePlatformHandleWrapper(
+      mojo::embedder::ScopedPlatformHandle(
+          mojo::embedder::PlatformHandle(handle.socket.fd)),
+      &wrapped_handle);
+  if (wrap_result != MOJO_RESULT_OK) {
+    LOG(WARNING) << "Pipe failed to wrap handles. Closing: " << wrap_result;
+    callback.Run(mojo::ScopedHandle());
+    return;
+  }
+  callback.Run(mojo::ScopedHandle(mojo::Handle(wrapped_handle)));
+}
+
+}  // namespace content