Fix background blending for some cases where it did not work at all. The fix adds the blendMode par…

Source/core/platform/graphics/ImageBuffer.cpp

 /*
  * Copyright (c) 2008, Google Inc. All rights reserved.
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. 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
@@ skipping 236 matching lines @@
 {
     if (!isValid())
         return;
 
     const SkBitmap& bitmap = *m_context->bitmap();
     RefPtr<Image> image = BitmapImage::create(NativeImageSkia::create(drawNeedsCopy(m_context.get(), context) ? deepSkBitmapCopy(bitmap) : bitmap));
     context->drawImage(image.get(), destRect, srcRect, op, blendMode, DoNotRespectImageOrientation, useLowQualityScale);
 }
 
 void ImageBuffer::drawPattern(GraphicsContext* context, const FloatRect& srcRect, const FloatSize& scale,
-    const FloatPoint& phase, CompositeOperator op, const FloatRect& destRect)
+    const FloatPoint& phase, CompositeOperator op, const FloatRect& destRect, BlendMode blendMode)
 {
     if (!isValid())
         return;
 
     const SkBitmap& bitmap = *m_context->bitmap();
     RefPtr<Image> image = BitmapImage::create(NativeImageSkia::create(drawNeedsCopy(m_context.get(), context) ? deepSkBitmapCopy(bitmap) : bitmap));
-    image->drawPattern(context, srcRect, scale, phase, op, destRect);
+    image->drawPattern(context, srcRect, scale, phase, op, destRect, blendMode);
 }
 
 void ImageBuffer::transformColorSpace(ColorSpace srcColorSpace, ColorSpace dstColorSpace)
 {
     if (srcColorSpace == dstColorSpace)
         return;
 
     // only sRGB <-> linearRGB are supported at the moment
     if ((srcColorSpace != ColorSpaceLinearRGB && srcColorSpace != ColorSpaceDeviceRGB)
         || (dstColorSpace != ColorSpaceLinearRGB && dstColorSpace != ColorSpaceDeviceRGB))
@@ skipping 214 matching lines @@
     if (!encodeImage(imageData, mimeType, quality, &encodedImage))
         return "data:,";
 
     Vector<char> base64Data;
     base64Encode(encodedImage, base64Data);
 
     return "data:" + mimeType + ";base64," + base64Data;
 }
 
 } // namespace WebCore