Make filters use SkImage instead of SkBitmap

src/image/SkImage.cpp

Index: src/image/SkImage.cpp
diff --git a/src/image/SkImage.cpp b/src/image/SkImage.cpp
index f427755d470dc4be61f436895e780c5b2fc542e9..995106eb78aaaa818edaec4eb457e90100ed2143 100644
--- a/src/image/SkImage.cpp
+++ b/src/image/SkImage.cpp
@@ -178,4 +178,35 @@ SkImage* SkImage_Base::onNewImage(int newWidth, int newHeight, const SkIRect* su
     return surface->newImageSnapshot();
 }
 
+inline static bool read_image_as_n32_bitmap(const SkImage* image, SkBitmap* bitmap) {
+    SkBitmap tmp;
+    if (!as_IB(image)->getROPixels(&tmp)) {
+        return false;
+    }
+    if (tmp.colorType() != kN32_SkColorType) {
+        return false;
+    }
+
+    tmp.lockPixels();
+    bitmap->swap(tmp);
+    return true;
+}
+
+SkAutoAdoptImageAsN32Bitmap::SkAutoAdoptImageAsN32Bitmap(SkAutoTUnref<const SkImage>& image,
+                                                         SkBitmap* bitmap)
+    : fBitmap(NULL) {
+    if (read_image_as_n32_bitmap(image, bitmap)) {
+        fBitmap = bitmap;
+        image.reset(NULL);
+    }
+}
+
+SkAutoImageAsN32Bitmap::SkAutoImageAsN32Bitmap(const SkImage* image, SkBitmap* bitmap)
+    : fBitmap(NULL) {
+    if (read_image_as_n32_bitmap(image, bitmap)) {
+        fBitmap = bitmap;
+    }
+}
+
+