Introduce a client minimum picture pool size

content/common/gpu/media/vt_video_decode_accelerator.cc

Index: content/common/gpu/media/vt_video_decode_accelerator.cc
diff --git a/content/common/gpu/media/vt_video_decode_accelerator.cc b/content/common/gpu/media/vt_video_decode_accelerator.cc
index 0aeab2bfcc331d9567af823f792f37f4c0df4ab1..5827dd091742c74aad52062818fe68efacb35737 100644
--- a/content/common/gpu/media/vt_video_decode_accelerator.cc
+++ b/content/common/gpu/media/vt_video_decode_accelerator.cc
@@ -291,6 +291,7 @@ VTVideoDecodeAccelerator::VTVideoDecodeAccelerator(
       make_context_current_(make_context_current),
       client_(nullptr),
       state_(STATE_DECODING),
+      num_picture_buffers_(kNumPictureBuffers),
       format_(nullptr),
       session_(nullptr),
       last_sps_id_(-1),
@@ -309,10 +310,14 @@ VTVideoDecodeAccelerator::~VTVideoDecodeAccelerator() {
 
 bool VTVideoDecodeAccelerator::Initialize(
     media::VideoCodecProfile profile,
+    uint32_t min_picture_count,
     Client* client) {
   DCHECK(gpu_thread_checker_.CalledOnValidThread());
   client_ = client;
 
+  num_picture_buffers_ = std::max(min_picture_count,
+                                  static_cast<uint32_t>(kNumPictureBuffers));
+
   if (!InitializeVideoToolbox())
     return false;
 
@@ -967,7 +972,7 @@ bool VTVideoDecodeAccelerator::ProcessFrame(const Frame& frame) {
       // Request new pictures.
       picture_size_ = frame.coded_size;
       client_->ProvidePictureBuffers(
-          kNumPictureBuffers, coded_size_, GL_TEXTURE_RECTANGLE_ARB);
+          num_picture_buffers_, coded_size_, GL_TEXTURE_RECTANGLE_ARB);
       return false;
     }
     if (!SendFrame(frame))