Merge 138170

Source/WebCore/platform/image-encoders/skia/PNGImageEncoder.cpp

 /*
  * Copyright (c) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 100 matching lines @@
 
     png_write_end(png, info);
     png_destroy_write_struct(&png, &info);
     return true;
 }
 
 bool PNGImageEncoder::encode(const SkBitmap& bitmap, Vector<unsigned char>* output)
 {
     SkAutoLockPixels bitmapLock(bitmap);
 
-    if (bitmap.config() != SkBitmap::kARGB_8888_Config)
+    if (bitmap.config() != SkBitmap::kARGB_8888_Config || !bitmap.getPixels())
         return false; // Only support 32 bit/pixel skia bitmaps.
 
     return encodePixels(IntSize(bitmap.width(), bitmap.height()), static_cast<unsigned char*>(bitmap.getPixels()), true, output);
 }
 
 bool PNGImageEncoder::encode(const ImageData& imageData, Vector<unsigned char>* output)
 {
     return encodePixels(imageData.size(), imageData.data()->data(), false, output);
 }
 
 } // namespace WebCore