New layers API for Views.

This API can be used to back a view and its children with either a
software layer (bitmap) or hardware layer (FBO). Layers have
various usages, including color filtering and performance
improvements during animations.

Change-Id: Ifc3bea847918042730fc5a8c2d4206dd6c9420a3
diff --git a/libs/hwui/Layer.h b/libs/hwui/Layer.h
index a780183..7d54d3b 100644
--- a/libs/hwui/Layer.h
+++ b/libs/hwui/Layer.h
@@ -26,6 +26,7 @@
 #include <SkXfermode.h>
 
 #include "Rect.h"
+#include "SkiaColorFilter.h"
 
 namespace android {
 namespace uirenderer {
@@ -93,6 +94,11 @@
      * have been drawn.
      */
     Region region;
+
+    /**
+     * Color filter used to draw this layer. Optional.
+     */
+    SkiaColorFilter* colorFilter;
 }; // struct Layer
 
 }; // namespace uirenderer