cc: zero/one-copy based on shared memory on IOS uses GL_TEXTURE_2D, not GL_TEXTURE_RECTANGLE_ARB.

cc/trees/layer_tree_settings.h

Index: cc/trees/layer_tree_settings.h
diff --git a/cc/trees/layer_tree_settings.h b/cc/trees/layer_tree_settings.h
index 3c2a72b7a9448d9cd7cd433021906a0689967832..0c3f9afd1df61faab5f2314faecdef86a844b44d 100644
--- a/cc/trees/layer_tree_settings.h
+++ b/cc/trees/layer_tree_settings.h
@@ -74,6 +74,7 @@ class CC_EXPORT LayerTreeSettings {
   bool use_one_copy;
   bool use_zero_copy;
   bool use_image_external;
+  bool use_image_io_surface;

[reveman, 2014/12/03 02:19:42]

I can see that this might have been confusing but "use_image_external" does not
refer to CHROMIUM_image. It's "image" as in OES_EGL_image_external. This code
should preferably not be aware of the existence of IOSurface backed GPU memory
buffers.

This should be "use_texture_rectangle" instead of "use_image_io_surface". Or
maybe better, we replace use_image_external+use_texture_rectangle with a texture
target enum.

   bool ignore_root_layer_flings;
   size_t scheduled_raster_task_limit;
   bool use_occlusion_for_tile_prioritization;