Allow Resize to be called w/ a preallocated pixmap

src/core/SkBitmapScaler.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkBitmapScaler_DEFINED
 #define SkBitmapScaler_DEFINED
 
@@ skipping 11 matching lines @@
         RESIZE_BOX,
         RESIZE_TRIANGLE,
         RESIZE_LANCZOS3,
         RESIZE_HAMMING,
         RESIZE_MITCHELL,
 
         RESIZE_FirstMethod = RESIZE_BOX,
         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);
 
      /** Platforms can also optionally overwrite the convolution functions
         if we have SIMD versions of them.
       */
 
     static void PlatformConvolutionProcs(SkConvolutionProcs*);
 };
 
 #endif