media: Add GpuMojoMediaClient.

content/gpu/gpu_child_thread.cc

Index: content/gpu/gpu_child_thread.cc
diff --git a/content/gpu/gpu_child_thread.cc b/content/gpu/gpu_child_thread.cc
index 994caed88c3cc88072e544cbbac1564c6ba2b8c9..1ff57f04cfee1e824f9a9e83b7630d7a766a8ccc 100644
--- a/content/gpu/gpu_child_thread.cc
+++ b/content/gpu/gpu_child_thread.cc
@@ -359,7 +359,8 @@ void GpuChildThread::OnInitialize(const gpu::GpuPreferences& gpu_preferences) {
       new media::MediaGpuChannelManager(gpu_channel_manager_.get()));
 
   // Only set once per process instance.
-  service_factory_.reset(new GpuServiceFactory);
+  service_factory_.reset(new GpuServiceFactory(
+      media_gpu_channel_manager_.get()));

[xhwang, 2016/11/23 06:58:03]

service_factory_ should be destroyed before media_gpu_channel_manager_ since
it's holding the raw ptr. Please add comments in the .h file to make this clear
(just in case someone switch the declaration order).

[sandersd (OOO until July 31), 2016/11/23 21:21:02]

This is actually safe due to the details of how the GPU child thread shuts down,
but I've changed everything over to use weak pointers. This makes the expected
usage pattern much clearer.

 
   GetInterfaceRegistry()->AddInterface(base::Bind(
       &GpuChildThread::BindServiceFactoryRequest, base::Unretained(this)));