Don't require VDAs to return all PictureBuffers at once.

media/filters/gpu_video_decoder.cc

Index: media/filters/gpu_video_decoder.cc
diff --git a/media/filters/gpu_video_decoder.cc b/media/filters/gpu_video_decoder.cc
index b7229f00124e94c3c77d383ed47639b94336984f..18bef573952a1f838f01d0ba11c395aaf807f197 100644
--- a/media/filters/gpu_video_decoder.cc
+++ b/media/filters/gpu_video_decoder.cc
@@ -68,6 +68,7 @@ GpuVideoDecoder::GpuVideoDecoder(GpuVideoAcceleratorFactories* factories)
       next_picture_buffer_id_(0),
       next_bitstream_buffer_id_(0),
       available_pictures_(0),
+      can_stall_anytime_(false),
       weak_factory_(this) {
   DCHECK(factories_);
 }
@@ -154,7 +155,10 @@ void GpuVideoDecoder::Initialize(const VideoDecoderConfig& config,
     return;
   }
 
-  if (!IsProfileSupported(config.profile(), config.coded_size())) {
+  VideoDecodeAccelerator::Capabilities capabilities =
+      factories_->GetVideoDecodeAcceleratorCapabilities();
+  if (!IsProfileSupported(capabilities, config.profile(),
+                          config.coded_size())) {
     DVLOG(1) << "Profile " << config.profile() << " or coded size "
              << config.coded_size().ToString() << " not supported.";
     bound_init_cb.Run(false);
@@ -162,6 +166,8 @@ void GpuVideoDecoder::Initialize(const VideoDecoderConfig& config,
   }
 
   config_ = config;
+  can_stall_anytime_ = capabilities.flags &
+                       VideoDecodeAccelerator::Capabilities::CAN_STALL_ANY_TIME;
   needs_bitstream_conversion_ = (config.codec() == kCodecH264);
   output_cb_ = BindToCurrentLoop(output_cb);
 
@@ -351,9 +357,9 @@ bool GpuVideoDecoder::NeedsBitstreamConversion() const {
 
 bool GpuVideoDecoder::CanReadWithoutStalling() const {
   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
-  return
-      next_picture_buffer_id_ == 0 ||  // Decode() will ProvidePictureBuffers().
-      available_pictures_ > 0;
+  return next_picture_buffer_id_ ==
+             0 ||  // Decode() will ProvidePictureBuffers().
+         (!can_stall_anytime_ && available_pictures_ > 0);

[Pawel Osciak, 2015/12/05 00:18:55]

The indents here seem wrong...

[liberato (no reviews please), 2015/12/07 19:04:39]

not sure, but it's what cl format does.

[Pawel Osciak, 2015/12/09 01:31:48]

Maybe it gets confused by the inline comment? I think this warrants a more
detailed comment than the existing one anyway though, so perhaps we could have a
comment explaining the whole condition above the return please?

 }
 
 int GpuVideoDecoder::GetMaxDecodeRequests() const {
@@ -640,11 +646,13 @@ void GpuVideoDecoder::NotifyError(media::VideoDecodeAccelerator::Error error) {
   DestroyVDA();
 }
 
-bool GpuVideoDecoder::IsProfileSupported(VideoCodecProfile profile,
-                                         const gfx::Size& coded_size) {
+bool GpuVideoDecoder::IsProfileSupported(
+    const VideoDecodeAccelerator::Capabilities& capabilities,
+    VideoCodecProfile profile,
+    const gfx::Size& coded_size) {
   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
-  VideoDecodeAccelerator::SupportedProfiles supported_profiles =
-      factories_->GetVideoDecodeAcceleratorSupportedProfiles();
+  const VideoDecodeAccelerator::SupportedProfiles& supported_profiles =
+      capabilities.supported_profiles;
   for (const auto& supported_profile : supported_profiles) {

[Pawel Osciak, 2015/12/05 00:18:55]

Nit: Personally I'd just s/supported_profiles/capabilities.supported_profiles/
and remove l.654-655, but up to you.

[liberato (no reviews please), 2015/12/07 19:04:39]

Done.

     if (profile == supported_profile.profile) {
       return IsCodedSizeSupported(coded_size,