Make drawImage a virtual on SkDevice

src/core/SkPaintPriv.cpp

Index: src/core/SkPaintPriv.cpp
diff --git a/src/core/SkPaintPriv.cpp b/src/core/SkPaintPriv.cpp
index c6957cd1cafe29ba19b76937a3d10999c7680927..3ced57392934e1f5b6a5fbb993c9c7f7be9acab9 100644
--- a/src/core/SkPaintPriv.cpp
+++ b/src/core/SkPaintPriv.cpp
@@ -9,6 +9,7 @@
 
 #include "SkBitmap.h"
 #include "SkColorFilter.h"
+#include "SkImage.h"
 #include "SkPaint.h"
 #include "SkShader.h"
 
@@ -49,3 +50,8 @@ bool isPaintOpaque(const SkPaint* paint, const SkBitmap* bmpReplacesShader) {
 
     return isPaintOpaque(paint, contentType);
 }
+
+bool isPaintOpaque(const SkPaint* paint, const SkImage* image) {
+    return isPaintOpaque(paint, image->isOpaque() ?
+                         kOpaque_SkPaintBitmapOpacity : kUnknown_SkPaintBitmapOpacity);
+}