Update from https://crrev.com/316786

cc/layers/draw_properties.h

Index: cc/layers/draw_properties.h
diff --git a/cc/layers/draw_properties.h b/cc/layers/draw_properties.h
index 5c78000226875bc1c67d804b0c945211d8f656c4..7cf89e756cab62bdaec717c52ecf2fdfd814690a 100644
--- a/cc/layers/draw_properties.h
+++ b/cc/layers/draw_properties.h
@@ -6,6 +6,7 @@
 #define CC_LAYERS_DRAW_PROPERTIES_H_
 
 #include "base/memory/scoped_ptr.h"
+#include "cc/trees/occlusion.h"
 #include "third_party/skia/include/core/SkXfermode.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/transform.h"
@@ -50,6 +51,9 @@ struct CC_EXPORT DrawProperties {
   // Transforms objects from content space to screen space (viewport space).
   gfx::Transform screen_space_transform;
 
+  // Known occlusion above the layer mapped to the content space of the layer.
+  Occlusion occlusion_in_content_space;
+
   // DrawProperties::opacity may be different than LayerType::opacity,
   // particularly in the case when a RenderSurface re-parents the layer's
   // opacity, or when opacity is compounded by the hierarchy.