gpu: Add CHROMIUM_copy_image extension.

ui/gl/gl_image_surface_texture.cc

Index: ui/gl/gl_image_surface_texture.cc
diff --git a/ui/gl/gl_image_surface_texture.cc b/ui/gl/gl_image_surface_texture.cc
index ef13671d6299cb53545252ee7f1bef343988051f..48a8f6e477e7ba28a67e9c29098de337ea8a2bb3 100644
--- a/ui/gl/gl_image_surface_texture.cc
+++ b/ui/gl/gl_image_surface_texture.cc
@@ -89,6 +89,14 @@ bool GLImageSurfaceTexture::CopyTexSubImage(unsigned target,
   return false;
 }
 
+bool GLImageSurfaceTexture::CopySubImageData(unsigned texture_id,
+                                             const gfx::Point& offset,
+                                             const gfx::Rect& rect,
+                                             GLFence* in_fence,
+                                             GLFence* out_fence) {
+  return false;
+}
+
 bool GLImageSurfaceTexture::ScheduleOverlayPlane(
     gfx::AcceleratedWidget widget,
     int z_order,