gpu: Add YCbCr 420v extension.

ui/gl/gl_image_io_surface.h

Index: ui/gl/gl_image_io_surface.h
diff --git a/ui/gl/gl_image_io_surface.h b/ui/gl/gl_image_io_surface.h
index 186f5a972e14bfa9c85a523ebbf61fa2eee197d8..4e76ead06982f3e593f86cf2ba73a45625d4e80b 100644
--- a/ui/gl/gl_image_io_surface.h
+++ b/ui/gl/gl_image_io_surface.h
@@ -64,6 +64,16 @@ class GL_EXPORT GLImageIOSurface : public GLImage {
   gfx::GenericSharedMemoryId io_surface_id_;
   base::ThreadChecker thread_checker_;
 
+  // GL state to support 420v IOSurface binding as RGBA.

[reveman, 2015/10/29 22:08:04]

nit: s/binding as RGBA/conversion to RGB/

[Daniele Castagna, 2015/10/30 23:51:57]

Done.

+  unsigned framebuffer_ = 0;
+  unsigned vertex_shader_ = 0;
+  unsigned fragment_shader_ = 0;
+  unsigned program_ = 0;
+  int size_location_ = -1;
+  unsigned vertex_buffer_ = 0;
+  static const char kVertexShader[];
+  static const char kFragmentShader[];

[reveman, 2015/10/29 22:08:03]

does these last two need to be here? anonymous namespace or just constants in
the function where they are used instead?

[Daniele Castagna, 2015/10/30 23:51:57]

No, moved in the anonymous namespace in the .mm file.

+
   DISALLOW_COPY_AND_ASSIGN(GLImageIOSurface);
 };