Introduce a client minimum picture pool size

content/common/gpu/media/v4l2_slice_video_decode_accelerator.cc

Index: content/common/gpu/media/v4l2_slice_video_decode_accelerator.cc
diff --git a/content/common/gpu/media/v4l2_slice_video_decode_accelerator.cc b/content/common/gpu/media/v4l2_slice_video_decode_accelerator.cc
index 5908fd61750db67fdf76115b686bbbdcccd64803..04a1fed45bce63b8ba1d2cd9755bc3ade94566f2 100644
--- a/content/common/gpu/media/v4l2_slice_video_decode_accelerator.cc
+++ b/content/common/gpu/media/v4l2_slice_video_decode_accelerator.cc
@@ -394,6 +394,7 @@ V4L2SliceVideoDecodeAccelerator::V4L2SliceVideoDecodeAccelerator(
       output_buffer_queued_count_(0),
       video_profile_(media::VIDEO_CODEC_PROFILE_UNKNOWN),
       output_format_fourcc_(0),
+      min_picture_count_(0),
       state_(kUninitialized),
       decoder_flushing_(false),
       decoder_resetting_(false),
@@ -434,6 +435,7 @@ void V4L2SliceVideoDecodeAccelerator::NotifyError(Error error) {
 
 bool V4L2SliceVideoDecodeAccelerator::Initialize(
     media::VideoCodecProfile profile,
+    uint32_t min_picture_count,
     VideoDecodeAccelerator::Client* client) {
   DVLOGF(3) << "profile: " << profile;
   DCHECK(child_task_runner_->BelongsToCurrentThread());
@@ -444,6 +446,7 @@ bool V4L2SliceVideoDecodeAccelerator::Initialize(
   client_ = client_ptr_factory_->GetWeakPtr();
 
   video_profile_ = profile;
+  min_picture_count_ = min_picture_count;
 
   if (video_profile_ >= media::H264PROFILE_MIN &&
       video_profile_ <= media::H264PROFILE_MAX) {
@@ -683,7 +686,9 @@ bool V4L2SliceVideoDecodeAccelerator::CreateOutputBuffers() {
   DCHECK(surfaces_at_device_.empty());
 
   visible_size_ = decoder_->GetPicSize();
-  size_t num_pictures = decoder_->GetRequiredNumOfPictures();
+  size_t num_pictures = std::max(min_picture_count_,
+                                 static_cast<uint32_t>(
+                                     decoder_->GetRequiredNumOfPictures()));
 
   DCHECK_GT(num_pictures, 0u);
   DCHECK(!visible_size_.IsEmpty());