Provide callback to create mojo AndroidOverlays to AVDA.

media/gpu/ipc/service/media_gpu_channel_manager.cc

Index: media/gpu/ipc/service/media_gpu_channel_manager.cc
diff --git a/media/gpu/ipc/service/media_gpu_channel_manager.cc b/media/gpu/ipc/service/media_gpu_channel_manager.cc
index 0a7e7c812e94c80a16e861c9743cfbea256743a9..96057629850354b24b12b3e1a62c7b2e2be4f1c1 100644
--- a/media/gpu/ipc/service/media_gpu_channel_manager.cc
+++ b/media/gpu/ipc/service/media_gpu_channel_manager.cc
@@ -28,7 +28,7 @@ void MediaGpuChannelManager::AddChannel(int32_t client_id) {
   DCHECK(gpu_channel);
   base::UnguessableToken channel_token = base::UnguessableToken::Create();
   std::unique_ptr<MediaGpuChannel> media_gpu_channel(
-      new MediaGpuChannel(gpu_channel, channel_token));
+      new MediaGpuChannel(gpu_channel, channel_token, overlay_factory_cb_));
   gpu_channel->SetUnhandledMessageListener(media_gpu_channel.get());
   media_gpu_channels_[client_id] = std::move(media_gpu_channel);
   channel_to_token_[client_id] = channel_token;
@@ -58,4 +58,9 @@ gpu::GpuChannel* MediaGpuChannelManager::LookupChannel(
   return channel_manager_->LookupChannel(it->second);
 }
 
+void MediaGpuChannelManager::SetOverlayFactory(
+    AndroidOverlayMojoFactoryCB overlay_factory_cb) {
+  overlay_factory_cb_ = std::move(overlay_factory_cb);
+}
+
 }  // namespace media