Merge 92388 - Set graphics context current before canvas.toDataURL().

Source/WebCore/platform/graphics/skia/ImageBufferSkia.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 343 matching lines @@
     }
 
     Vector<char> base64Data;
     base64Encode(*reinterpret_cast<Vector<char>*>(&encodedImage), base64Data);
 
     return "data:" + mimeType + ";base64," + base64Data;
 }
 
 String ImageBuffer::toDataURL(const String& mimeType, const double* quality) const
 {
+    m_context->platformContext()->makeGrContextCurrent();
     SkDevice* device = context()->platformContext()->canvas()->getDevice();
-    SkBitmap bitmap = device->accessBitmap(false);
-
-    // if we can't see the pixels directly, call readPixels() to get a copy.
-    // this could happen if the device is backed by a GPU.
-    bitmap.lockPixels(); // balanced by our destructor, or explicitly if getPixels() fails
-    if (!bitmap.getPixels()) {
-        bitmap.unlockPixels();
-        SkIRect bounds = SkIRect::MakeWH(device->width(), device->height());
-        if (!device->readPixels(bounds, &bitmap))
-            return "data:,";
-    }
-
-    return ImageToDataURL(bitmap, mimeType, quality);
+    return ImageToDataURL(device->accessBitmap(false), mimeType, quality);
 }
 
 String ImageDataToDataURL(const ImageData& source, const String& mimeType, const double* quality)
 {
     return ImageToDataURL(source, mimeType, quality);
 }
 
 } // namespace WebCore