Allow Resize to be called w/ a preallocated pixmap

src/core/SkBitmapScaler.h

Index: src/core/SkBitmapScaler.h
diff --git a/src/core/SkBitmapScaler.h b/src/core/SkBitmapScaler.h
index 03feec3e127c239eb4ac056d7845f748775242ab..3d734d6efc5a2dded5836975165941dabce10112 100644
--- a/src/core/SkBitmapScaler.h
+++ b/src/core/SkBitmapScaler.h
@@ -29,6 +29,16 @@ public:
         RESIZE_LastMethod = RESIZE_MITCHELL,
     };
 
+    /**
+     *  Given already-allocated src and dst pixmaps, this will scale the src pixels using the
+     *  specified resize-method and write the results into the pixels pointed to by dst.
+     */
+    static bool Resize(const SkPixmap& dst, const SkPixmap& src, ResizeMethod method);
+
+    /**
+     *  Helper function that manages allocating a bitmap to hold the dst pixels, and then calls
+     *  the pixmap version of Resize.
+     */
     static bool Resize(SkBitmap* result, const SkPixmap& src, ResizeMethod method,
                        int dest_width, int dest_height, SkBitmap::Allocator* = nullptr);