Introduce a client minimum picture pool size

content/common/gpu/media/dxva_video_decode_accelerator.cc

Index: content/common/gpu/media/dxva_video_decode_accelerator.cc
diff --git a/content/common/gpu/media/dxva_video_decode_accelerator.cc b/content/common/gpu/media/dxva_video_decode_accelerator.cc
index 568b128e1d1bdea5e0d98bed04fda5db6b54b733..6a578dd157efa8c1d81e16679ca32c6e39ab0f93 100644
--- a/content/common/gpu/media/dxva_video_decode_accelerator.cc
+++ b/content/common/gpu/media/dxva_video_decode_accelerator.cc
@@ -517,6 +517,7 @@ DXVAVideoDecodeAccelerator::DXVAVideoDecodeAccelerator(
       dx11_dev_manager_reset_token_(0),
       egl_config_(NULL),
       state_(kUninitialized),
+      num_picture_buffers_(kNumPictureBuffers),
       pictures_requested_(false),
       inputs_before_decode_(0),
       sent_drain_message_(false),
@@ -538,9 +539,13 @@ DXVAVideoDecodeAccelerator::~DXVAVideoDecodeAccelerator() {
 }
 
 bool DXVAVideoDecodeAccelerator::Initialize(media::VideoCodecProfile profile,
-                                           Client* client) {
+                                            uint32_t min_picture_count,
+                                            Client* client) {
   client_ = client;
 
+  num_picture_buffers_ = std::max(min_picture_count,
+                                  static_cast<uint32_t>(kNumPictureBuffers));
+
   main_thread_task_runner_ = base::MessageLoop::current()->task_runner();
 
   bool profile_supported = false;
@@ -777,9 +782,9 @@ void DXVAVideoDecodeAccelerator::AssignPictureBuffers(
   State state = GetState();
   RETURN_AND_NOTIFY_ON_FAILURE((state != kUninitialized),
       "Invalid state: " << state, ILLEGAL_STATE,);
-  RETURN_AND_NOTIFY_ON_FAILURE((kNumPictureBuffers == buffers.size()),
+  RETURN_AND_NOTIFY_ON_FAILURE((num_picture_buffers_ == buffers.size()),
       "Failed to provide requested picture buffers. (Got " << buffers.size() <<
-      ", requested " << kNumPictureBuffers << ")", INVALID_ARGUMENT,);
+      ", requested " << num_picture_buffers_ << ")", INVALID_ARGUMENT,);
 
   // Copy the picture buffers provided by the client to the available list,
   // and mark these buffers as available for use.
@@ -1479,7 +1484,7 @@ void DXVAVideoDecodeAccelerator::RequestPictureBuffers(int width, int height) {
   // This task could execute after the decoder has been torn down.
   if (GetState() != kUninitialized && client_) {
     client_->ProvidePictureBuffers(
-        kNumPictureBuffers,
+        num_picture_buffers_,
         gfx::Size(width, height),
         GL_TEXTURE_2D);
   }