Add image->bitmap

src/image/SkImage_Raster.cpp

Index: src/image/SkImage_Raster.cpp
diff --git a/src/image/SkImage_Raster.cpp b/src/image/SkImage_Raster.cpp
index 250e3624eaefeb8f0fc0a27d43ac5295d9e7b976..5f403d9cca2c0680a4257e69ffc89a7de2975e79 100644
--- a/src/image/SkImage_Raster.cpp
+++ b/src/image/SkImage_Raster.cpp
@@ -79,6 +79,7 @@ public:
                           const SkMatrix* localMatrix) const override;
 
     bool isOpaque() const override;
+    bool onAsBitmap(SkBitmap*, AsBitmapMode) const override;
 
     SkImage_Raster(const SkBitmap& bm, const SkSurfaceProps* props)
         : INHERITED(bm.width(), bm.height(), props)
@@ -262,3 +263,11 @@ bool SkImage_Raster::isOpaque() const {
     return fBitmap.isOpaque();
 }
 
+bool SkImage_Raster::onAsBitmap(SkBitmap* bitmap, AsBitmapMode mode) const {
+    if (kRO_AsBitmapMode == mode) {
+        bitmap->setInfo(fBitmap.info());
+        bitmap->setPixelRef(fBitmap.pixelRef(), fBitmap.pixelRefOrigin());
+        return true;
+    }
+    return this->INHERITED::onAsBitmap(bitmap, kRW_AsBitmapMode);
+}