Support external buffer import in VDA interface and add a V4L2SVDA impl.

content/common/gpu/media/gpu_video_decode_accelerator_factory_impl.cc

Index: content/common/gpu/media/gpu_video_decode_accelerator_factory_impl.cc
diff --git a/content/common/gpu/media/gpu_video_decode_accelerator_factory_impl.cc b/content/common/gpu/media/gpu_video_decode_accelerator_factory_impl.cc
index f6ec448a1229553744e0cbc3f22b3ca46c56c8ab..e4f3a35a5fbb2b785c902a9104a69a179a277d89 100644
--- a/content/common/gpu/media/gpu_video_decode_accelerator_factory_impl.cc
+++ b/content/common/gpu/media/gpu_video_decode_accelerator_factory_impl.cc
@@ -31,13 +31,6 @@
 
 namespace content {
 
-namespace {
-static base::WeakPtr<gpu::gles2::GLES2Decoder> GetEmptyGLES2Decoder() {
-  NOTREACHED() << "VDA requests a GLES2Decoder, but client did not provide it";
-  return base::WeakPtr<gpu::gles2::GLES2Decoder>();
-}
-}
-
 // static
 std::unique_ptr<GpuVideoDecodeAcceleratorFactoryImpl>
 GpuVideoDecodeAcceleratorFactoryImpl::Create(
@@ -46,7 +39,7 @@ GpuVideoDecodeAcceleratorFactoryImpl::Create(
     const BindGLImageCallback& bind_image_cb) {
   return base::WrapUnique(new GpuVideoDecodeAcceleratorFactoryImpl(
       get_gl_context_cb, make_context_current_cb, bind_image_cb,
-      base::Bind(&GetEmptyGLES2Decoder)));
+      GetGLES2DecoderCallback()));
 }
 
 // static
@@ -62,6 +55,13 @@ GpuVideoDecodeAcceleratorFactoryImpl::CreateWithGLES2Decoder(
 }
 
 // static
+std::unique_ptr<GpuVideoDecodeAcceleratorFactoryImpl>
+GpuVideoDecodeAcceleratorFactoryImpl::CreateWithNoGL() {
+  return Create(GetGLContextCallback(), MakeGLContextCurrentCallback(),
+                BindGLImageCallback());
+}
+
+// static
 gpu::VideoDecodeAcceleratorCapabilities
 GpuVideoDecodeAcceleratorFactoryImpl::GetDecoderCapabilities(
     const gpu::GpuPreferences& gpu_preferences) {