V4L2VideoDecodeAccelerator: support external buffer import

media/gpu/v4l2_video_encode_accelerator.cc

Index: media/gpu/v4l2_video_encode_accelerator.cc
diff --git a/media/gpu/v4l2_video_encode_accelerator.cc b/media/gpu/v4l2_video_encode_accelerator.cc
index 1ac5a18cfc4111742e36847a4e2aba944194ad78..afa57e185fcd15161c54eba7b41786dadfc9ffd1 100644
--- a/media/gpu/v4l2_video_encode_accelerator.cc
+++ b/media/gpu/v4l2_video_encode_accelerator.cc
@@ -182,8 +182,8 @@ bool V4L2VideoEncodeAccelerator::Initialize(VideoPixelFormat input_format,
     // processor and there will be no callbacks after processor destroys.
     if (!image_processor_->Initialize(
             input_format, device_input_format_, V4L2_MEMORY_USERPTR,
-            visible_size_, visible_size_, visible_size_, input_allocated_size_,
-            kImageProcBufferCount,
+            V4L2_MEMORY_MMAP, visible_size_, visible_size_, visible_size_,
+            input_allocated_size_, kImageProcBufferCount,
             base::Bind(&V4L2VideoEncodeAccelerator::ImageProcessorError,
                        base::Unretained(this)))) {
       LOG(ERROR) << "Failed initializing image processor";
@@ -259,7 +259,7 @@ void V4L2VideoEncodeAccelerator::Encode(const scoped_refptr<VideoFrame>& frame,
       // Unretained is safe because |this| owns image processor and there will
       // be no callbacks after processor destroys.
       image_processor_->Process(
-          frame, output_buffer_index,
+          frame, output_buffer_index, std::vector<int>(),
           base::Bind(&V4L2VideoEncodeAccelerator::FrameProcessed,
                      base::Unretained(this), force_keyframe,
                      frame->timestamp()));