Implement new RPDQ copy logic for CALayer promotion.

cc/output/ca_layer_overlay.h

Index: cc/output/ca_layer_overlay.h
diff --git a/cc/output/ca_layer_overlay.h b/cc/output/ca_layer_overlay.h
index e64f0d97f4457bf18a6a20882ec9873731e80a94..9ea4a8e4be6c700477ed4a0ec6cbdc54f88e31b1 100644
--- a/cc/output/ca_layer_overlay.h
+++ b/cc/output/ca_layer_overlay.h
@@ -5,8 +5,10 @@
 #ifndef CC_OUTPUT_CA_LAYER_OVERLAY_H_
 #define CC_OUTPUT_CA_LAYER_OVERLAY_H_
 
+#include "base/memory/linked_ptr.h"
 #include "base/memory/ref_counted.h"
 #include "cc/quads/render_pass.h"
+#include "cc/quads/render_pass_draw_quad.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkMatrix44.h"
 #include "ui/gfx/geometry/rect_f.h"
@@ -23,7 +25,7 @@ class CC_EXPORT CALayerOverlaySharedState
     : public base::RefCounted<CALayerOverlaySharedState> {
  public:
   CALayerOverlaySharedState() {}
-
+  CALayerOverlaySharedState& operator=(const CALayerOverlaySharedState& other);
   // Layers in a non-zero sorting context exist in the same 3D space and should
   // intersect.
   unsigned sorting_context_id = 0;
@@ -66,6 +68,13 @@ class CC_EXPORT CALayerOverlay {
 
   // If valid, the renderer must copy the contents of the render pass into an
   // overlay resource to use as the contents.
+  // If |rpdq| is present, then the renderer must use the new copy path.
+  // GLRenderer draws filter effects and copies the result into an IOSurface.
+  linked_ptr<RenderPassDrawQuad> rpdq;

[ccameron, 2016/08/04 01:46:01]

unique_ptr, or raw pointer. I'd prefer a raw ptr into the DrawQuadList, and just
not clear the DrawQuadList.

This could be a raw ptr if we were to not clear the DrawQuad list at
https://cs.chromium.org/chromium/src/cc/output/overlay_processor.cc?rcl=0&l=55

(And there's no good reason to clear the DrawQuad list there -- we make the
damage rect be empty, which makes us skip drawing the root render pass at 
https://cs.chromium.org/chromium/src/cc/output/direct_renderer.cc?rcl=1470251...
)

[erikchen, 2016/08/05 17:15:06]

Done.

+
+  // If |render_pass_id| and |filter_effects| are present, then the renderer
+  // must use the old copy path. The filters are serialized and passed to the CA
+  // compositor, which uses CA to draw the filter effects.
   RenderPassId render_pass_id;
   ui::CARendererLayerParams::FilterEffects filter_effects;
 };