Replace NativeImageSkia usage with SkBitmap in ImageFrame

Source/platform/graphics/skia/NativeImageSkia.h

 /*
  * Copyright (c) 2008, 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 83 matching lines @@
     {
         return adoptRef(new NativeImageSkia(m_image, m_resizedImage, m_cachedImageInfo, m_resizeRequests));
     }
 
     ~NativeImageSkia();
 
     // Returns the number of bytes of image data. This includes the cached
     // resized version if there is one.
     int decodedSize() const;
 
-    // Sets the immutable flag on the bitmap, indicating that the image data
-    // will not be modified any further. This is called by the image decoder
-    // when all data is complete, used by us to know whether we can cache
-    // resized images, and used by Skia for various optimizations.
-    void setDataComplete() { m_image.setImmutable(); }
-
     // Returns true if the entire image has been decoded.
     bool isDataComplete() const { return m_image.isImmutable(); }
 
     // Get reference to the internal SkBitmap representing this image.
     const SkBitmap& bitmap() const { return m_image; }
-    SkBitmap& bitmap() { return m_image; }
 
     // We can keep a resized version of the bitmap cached on this object.
     // This function will return true if there is a cached version of the given
     // scale and subset.
     bool hasResizedBitmap(const SkISize& scaledImageSize, const SkIRect& scaledImageSubset) const;
 
     // This will return an existing resized image subset, or generate a new one
     // of the specified size and subset and possibly cache it.
     //
     // scaledImageSize
@@ skipping 73 matching lines @@
     // those requests individually are small and would not otherwise be cached.
     //
     // We also track scaling information and destination subset for the scaled
     // image. See comments for ImageResourceInfo.
     mutable ImageResourceInfo m_cachedImageInfo;
     mutable int m_resizeRequests;
 };
 
 }
 #endif  // NativeImageSkia_h