Add an API to set the ColorFilter on a Paint object.

sky/engine/core/painting/Paint.cpp

Index: sky/engine/core/painting/Paint.cpp
diff --git a/sky/engine/core/painting/Paint.cpp b/sky/engine/core/painting/Paint.cpp
index a132a08252e57c6e2a5ef8cf9125bd0c58fbd6ff..549cd72dbd503a4a0f1b9cfb27ff790dd5b3641e 100644
--- a/sky/engine/core/painting/Paint.cpp
+++ b/sky/engine/core/painting/Paint.cpp
@@ -5,6 +5,7 @@
 #include "sky/engine/config.h"
 #include "sky/engine/core/painting/Paint.h"
 
+#include "sky/engine/core/painting/ColorFilter.h"
 #include "sky/engine/core/painting/DrawLooper.h"
 
 namespace blink {
@@ -23,4 +24,10 @@ void Paint::setDrawLooper(DrawLooper* looper)
     m_paint.setLooper(looper->looper());
 }
 
+void Paint::setColorFilter(ColorFilter* filter)
+{
+    ASSERT(filter);
+    m_paint.setColorFilter(filter->filter());
+}
+
 } // namespace blink