Introduce GpuVideoDecodeAcceleratorFactory.

media/video/video_decode_accelerator.cc

Index: media/video/video_decode_accelerator.cc
diff --git a/media/video/video_decode_accelerator.cc b/media/video/video_decode_accelerator.cc
index 4275d5fec83c744382fa20a99a2aebdd643162b8..fa7138b6e59f133ee599ea7feeb4d51cfbf55dd0 100644
--- a/media/video/video_decode_accelerator.cc
+++ b/media/video/video_decode_accelerator.cc
@@ -34,9 +34,11 @@ void VideoDecodeAccelerator::SetCdm(int cdm_id) {
   NOTREACHED() << "By default CDM is not supported.";
 }
 
-bool VideoDecodeAccelerator::CanDecodeOnIOThread() {
-  // GPU process subclasses must override this.
-  LOG(FATAL) << "This should only get called in the GPU process";
+bool VideoDecodeAccelerator::TryToSetupDecodeOnSeparateThread(
+    const base::WeakPtr<Client>& decode_client,
+    const scoped_refptr<base::SingleThreadTaskRunner>& decode_task_runner) {
+  // Implementations in the process that VDA runs in must override this.
+  LOG(FATAL) << "This may only be called in the same process as VDA impl.";
   return false;  // not reached
 }