Support low latency mode decoding in the H/W video decoder on Windows.

content/common/gpu/media/dxva_video_decode_accelerator.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/common/gpu/media/dxva_video_decode_accelerator.h"
 
 #if !defined(OS_WIN)
 #error This file should only be built on Windows.
 #endif   // !defined(OS_WIN)
 
@@ skipping 866 matching lines @@
 
   UINT32 dxva = 0;
   hr = attributes->GetUINT32(MF_SA_D3D_AWARE, &dxva);
   RETURN_ON_HR_FAILURE(hr, "Failed to check if decoder supports DXVA", false);
 
   if (codec_ == media::kCodecH264) {
     hr = attributes->SetUINT32(CODECAPI_AVDecVideoAcceleration_H264, TRUE);
     RETURN_ON_HR_FAILURE(hr, "Failed to enable DXVA H/W decoding", false);
   }
 
+  hr = attributes->SetUINT32(CODECAPI_AVLowLatencyMode, TRUE);
+  if (SUCCEEDED(hr)) {
+    DVLOG(1) << "Successfully set Low latency mode on decoder.";
+  } else {
+    DVLOG(1) << "Failed to set Low latency mode on decoder. Error: " << hr;
+  }
   return true;
 }
 
 bool DXVAVideoDecodeAccelerator::SetDecoderMediaTypes() {
   RETURN_ON_FAILURE(SetDecoderInputMediaType(),
                     "Failed to set decoder input media type", false);
   return SetDecoderOutputMediaType(MFVideoFormat_NV12);
 }
 
 bool DXVAVideoDecodeAccelerator::SetDecoderInputMediaType() {
@@ skipping 722 matching lines @@
     FROM_HERE,
     base::Bind(&DXVAVideoDecodeAccelerator::CopySurfaceComplete,
                weak_this_factory_.GetWeakPtr(),
                src_surface,
                dest_surface,
                picture_buffer_id,
                input_buffer_id));
 }
 
 }  // namespace content