Make filters use SkImage instead of SkBitmap

include/core/SkImage.h

Index: include/core/SkImage.h
diff --git a/include/core/SkImage.h b/include/core/SkImage.h
index ec855166195d863bd014156deda1bf03742f2451..5d2ae24ef752490e7d24072242286a4aecd2ef62 100644
--- a/include/core/SkImage.h
+++ b/include/core/SkImage.h
@@ -187,4 +187,38 @@ private:
     void drawRect(SkCanvas*, const SkRect* src, const SkRect& dst, const SkPaint*) const;
 };
 
+/** A helper for common in pixel access done with CPU: lock pixels of the rendering of the
+ * image in N32 format, or fail. The condition bitmap->getPixels() != NULL signifies success.
+ * Will unref the image if succesful, as this may save memory.
+ */
+class SkAutoAdoptImageAsN32Bitmap : SkNoncopyable {
+public:
+    /**
+     * @param image image to adopt as bitmap. will be reset(NULL) if operation is successful.
+     */
+    SkAutoAdoptImageAsN32Bitmap(SkAutoTUnref<const SkImage>& image, SkBitmap* bitmap);
+    ~SkAutoAdoptImageAsN32Bitmap() {
+        if (fBitmap) {
+            fBitmap->unlockPixels();
+        }
+    }
+private:
+    SkBitmap* fBitmap;
+};
+
+/** A helper for common in pixel access done with CPU: lock pixels of the rendering of the
+ * image in N32 format, or fail. The condition bitmap->getPixels() != NULL signifies success.
+ */
+class SkAutoImageAsN32Bitmap : SkNoncopyable {
+public:
+    SkAutoImageAsN32Bitmap(const SkImage* image, SkBitmap* bitmap);
+    ~SkAutoImageAsN32Bitmap() {
+        if (fBitmap) {
+            fBitmap->unlockPixels();
+        }
+    }
+private:
+    SkBitmap* fBitmap;
+};
+
 #endif