Fix mess in ImageDecoder::setRGB* methods after r153004

Source/core/platform/image-decoders/ImageDecoder.h

 /*
  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 172 matching lines @@
         inline void setRGBA(PixelData* dest, unsigned r, unsigned g, unsigned b, unsigned a)
         {
             if (m_premultiplyAlpha)
                 setRGBAPremultiply(dest, r, g, b, a);
             else
                 setRGBARaw(dest, r, g, b, a);
         }
 
         inline void setRGBAPremultiply(PixelData* dest, unsigned r, unsigned g, unsigned b, unsigned a)
         {
-            ASSERT(m_premultiplyAlpha);
-
-            if (!a) {
-                *dest = 0;
-                return;
-            }
             if (a < 255) {
+                if (!a) {
+                    *dest = 0;
+                    return;
+                }
                 unsigned alphaMult = a * fixPointMult;
                 r = fixPointUnsignedMultiply(r, alphaMult);
                 g = fixPointUnsignedMultiply(g, alphaMult);
                 b = fixPointUnsignedMultiply(b, alphaMult);
             }
 
             // Call the "NoCheck" version since we may deliberately pass non-premultiplied
             // values, and we don't want an assert.
             *dest = SkPackARGB32NoCheck(a, r, g, b);
         }
 
         inline void setRGBARaw(PixelData* dest, unsigned r, unsigned g, unsigned b, unsigned a)
         {
-            ASSERT(!m_premultiplyAlpha);
-
             *dest = SkPackARGB32NoCheck(a, r, g, b);
         }
 
     private:
         int width() const
         {
             return m_bitmap->bitmap().width();
         }
 
         int height() const
@@ skipping 239 matching lines @@
 
         IntSize m_size;
         bool m_sizeAvailable;
         bool m_isAllDataReceived;
         bool m_failed;
     };
 
 } // namespace WebCore
 
 #endif