media: Optimize HW Video to 2D Canvas copy.

media/filters/context_3d_provider.h

+// Copyright (c) 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MEDIA_FILTERS_CONTEXT_3D_PROVIDER_H_
+#define MEDIA_FILTERS_CONTEXT_3D_PROVIDER_H_
+
+class GrContext;
+
+namespace gpu {
+namespace gles2 {
+class GLES2Interface;
+}
+}
+
+namespace media {
+
+// This struct can be used to make media use gpu::gles2::GLES2Interface and
+// GrContext.
+// Usage:
+// gpu::gles2::GLES2Interface* gl = ...;
+// GrContext* gr_context = ...;
+// Context3DProvider provider(gl, gr_context);
+
+struct Context3DProvider {

[jamesr, 2014/11/24 22:19:50]

cc::ContextProvider exists to provide a shared ownership model of the context. 
this appears to just have raw pointers (i.e. no ownership) of the underlying gl
and gr contexts.  I'm not sure what value bundling the two pointers together
provides, but whatever it is it should definitely not have a name so similar to
cc::ContextProvider since it doesn't provide the same lifetime properties.

+  Context3DProvider() : gl(nullptr), gr_context(nullptr) {}
+  Context3DProvider(gpu::gles2::GLES2Interface* gl_,
+                    class GrContext* gr_context_)
+      : gl(gl_), gr_context(gr_context_) {}
+
+  gpu::gles2::GLES2Interface* gl;
+  class GrContext* gr_context;
+};
+
+}  // namespace media
+
+#endif  // MEDIA_FILTERS_CONTEXT_3D_PROVIDER_H_