WebGL: GL_RGB emulation for IOSurface backed textures. [For reference only]

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 d8b731828f26d674176401f38b89489857fed367..cb949a45c047f8b7d499587e75b7574aa1b814d9 100644
--- a/ui/gl/gl_image_io_surface.h
+++ b/ui/gl/gl_image_io_surface.h
@@ -49,6 +49,7 @@ class GL_EXPORT GLImageIOSurface : public GLImage {
   void OnMemoryDump(base::trace_event::ProcessMemoryDump* pmd,
                     uint64_t process_tracing_id,
                     const std::string& dump_name) override;
+  bool EmulatingRGB() const override;
 
   gfx::GenericSharedMemoryId io_surface_id() const { return io_surface_id_; }
   base::ScopedCFTypeRef<IOSurfaceRef> io_surface();
@@ -62,7 +63,13 @@ class GL_EXPORT GLImageIOSurface : public GLImage {
 
  private:
   const gfx::Size size_;
-  const unsigned internalformat_;
+  unsigned internalformat_;
+
+  // This class is capable of emulating RGB internal format with RGBA
+  // internal format. The member |internalformat_| holds the format
+  // exposed to the command buffer. |desired_internalformat_| holds the format
+  // desired by the caller of the constructor of this object.
+  const unsigned desired_internalformat_;
   gfx::BufferFormat format_;
   base::ScopedCFTypeRef<IOSurfaceRef> io_surface_;
   gfx::GenericSharedMemoryId io_surface_id_;