VideoToolbox/SharedImage: Plumb SharedImageStub

Add a method through which VTVideoDecodeAccelerator will be able to
access a SharedImageStub. In this case we've hung it off of
VdaVideoDecoder's implementation of the VideoDecodeAccelerator::Client
implementation. An alternative could be the GpuVideoDecodeGLClient, but
that's a GL thing and after this change, VTVideoDecodeAccelerator won't
use any GL things.

Bug: 1108909
Change-Id: I46e7e92eaa90e7fb89c4582e53d985c3ae1d8d4c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2333304
Commit-Queue: ccameron <ccameron@chromium.org>
Reviewed-by: Dan Sanders <sandersd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#795706}

media/gpu/command_buffer_helper.cc

@@ -62,6 +62,12 @@ class CommandBufferHelperImpl
     return decoder_helper_->GetGLContext();
   }
 
+  gpu::SharedImageStub* GetSharedImageStub() override {
+    if (!stub_)
+      return nullptr;
+    return stub_->channel()->shared_image_stub();
+  }
+
   bool HasStub() override {
     DVLOG(4) << __func__;
     DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);

media/gpu/command_buffer_helper.h

@@ -20,6 +20,7 @@ namespace gpu {
 class CommandBufferStub;
 class SharedImageBacking;
 class SharedImageRepresentationFactoryRef;
+class SharedImageStub;
 class TextureBase;
 }  // namespace gpu
 
@@ -52,6 +53,9 @@ class MEDIA_GPU_EXPORT CommandBufferHelper
   // EGLImages. New clients should use more specialized accessors instead.
   virtual gl::GLContext* GetGLContext() = 0;
 
+  // Retrieve the interface through which to create shared images.
+  virtual gpu::SharedImageStub* GetSharedImageStub() = 0;
+
   // Checks whether the stub has been destroyed.
   virtual bool HasStub() = 0;
 

media/gpu/ipc/service/vda_video_decoder.cc

@@ -757,6 +757,10 @@ void VdaVideoDecoder::NotifyError(VideoDecodeAccelerator::Error error) {
                                 parent_weak_this_, error));
 }
 
+gpu::SharedImageStub* VdaVideoDecoder::GetSharedImageStub() const {
+  return command_buffer_helper_->GetSharedImageStub();
+}
+
 void VdaVideoDecoder::NotifyErrorOnParentThread(
     VideoDecodeAccelerator::Error error) {
   DVLOG(1) << __func__ << "(" << error << ")";

media/gpu/ipc/service/vda_video_decoder.h

@@ -128,6 +128,7 @@ class VdaVideoDecoder : public VideoDecoder,
   void NotifyFlushDone() override;
   void NotifyResetDone() override;
   void NotifyError(VideoDecodeAccelerator::Error error) override;
+  gpu::SharedImageStub* GetSharedImageStub() const override;
 
   // Tasks and thread hopping.
   static void CleanupOnGpuThread(std::unique_ptr<VdaVideoDecoder>);

media/gpu/test/fake_command_buffer_helper.cc

@@ -66,6 +66,10 @@ gl::GLContext* FakeCommandBufferHelper::GetGLContext() {
   return nullptr;
 }
 
+gpu::SharedImageStub* FakeCommandBufferHelper::GetSharedImageStub() {
+  return nullptr;
+}
+
 bool FakeCommandBufferHelper::HasStub() {
   return has_stub_;
 }

media/gpu/test/fake_command_buffer_helper.h

@@ -39,6 +39,7 @@ class FakeCommandBufferHelper : public CommandBufferHelper {
 
   // CommandBufferHelper implementation.
   gl::GLContext* GetGLContext() override;
+  gpu::SharedImageStub* GetSharedImageStub() override;
   bool HasStub() override;
   bool MakeContextCurrent() override;
   std::unique_ptr<gpu::SharedImageRepresentationFactoryRef> Register(

media/video/video_decode_accelerator.cc

@@ -66,6 +66,11 @@ void VideoDecodeAccelerator::Client::ProvidePictureBuffersWithVisibleRect(
   }
 }
 
+gpu::SharedImageStub* VideoDecodeAccelerator::Client::GetSharedImageStub()
+    const {
+  return nullptr;
+}
+
 VideoDecodeAccelerator::~VideoDecodeAccelerator() = default;
 
 void VideoDecodeAccelerator::Decode(scoped_refptr<DecoderBuffer> buffer,

media/video/video_decode_accelerator.h

@@ -32,6 +32,10 @@ namespace base {
 class SingleThreadTaskRunner;
 }
 
+namespace gpu {
+class SharedImageStub;
+}
+
 namespace media {
 
 // Video decoder interface.
@@ -254,6 +258,10 @@ class MEDIA_EXPORT VideoDecodeAccelerator {
     // a false return value there.
     virtual void NotifyError(Error error) = 0;
 
+    // Return the SharedImageStub through which SharedImages may be created.
+    // Default implementation returns nullptr.
+    virtual gpu::SharedImageStub* GetSharedImageStub() const;
+
    protected:
     virtual ~Client() {}
   };