Add initialization callback support for Video Decoder PPAPI.

content/renderer/gpu_video_decode_accelerator_host.cc

Index: content/renderer/gpu_video_decode_accelerator_host.cc
diff --git a/content/renderer/gpu_video_decode_accelerator_host.cc b/content/renderer/gpu_video_decode_accelerator_host.cc
index cb5b3db289549e6c250a6ed2be94de793e78ede0..d881d3248e49ffac5bc0ee17966d4eec75aa3a8a 100644
--- a/content/renderer/gpu_video_decode_accelerator_host.cc
+++ b/content/renderer/gpu_video_decode_accelerator_host.cc
@@ -46,6 +46,8 @@ bool GpuVideoDecodeAcceleratorHost::OnMessageReceived(const IPC::Message& msg) {
                         OnProvidePictureBuffer)
     IPC_MESSAGE_HANDLER(AcceleratedVideoDecoderHostMsg_CreateDone,
                         OnCreateDone)
+    IPC_MESSAGE_HANDLER(AcceleratedVideoDecoderHostMsg_InitializeDone,
+                        OnInitializeDone)
     IPC_MESSAGE_HANDLER(AcceleratedVideoDecoderHostMsg_PictureReady,
                         OnPictureReady)
     IPC_MESSAGE_HANDLER(AcceleratedVideoDecoderHostMsg_FlushDone,
@@ -170,6 +172,10 @@ void GpuVideoDecodeAcceleratorHost::OnCreateDone(int32 decoder_id) {
   }
 }
 
+void GpuVideoDecodeAcceleratorHost::OnInitializeDone() {
+  client_->NotifyInitializeDone();
+}
+
 void GpuVideoDecodeAcceleratorHost::OnPictureReady(
     int32 picture_buffer_id, int32 bitstream_buffer_id) {
   media::Picture picture(picture_buffer_id, bitstream_buffer_id);