Refactoring ImageBuffer to decouple it from Canvas2DLayerBridge

Source/core/frame/Frame.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Simon Hausmann <hausmann@kde.org>
  *                     2000 Stefan Schimanski <1Stein@gmx.de>
  *                     2001 George Staikos <staikos@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2005 Alexey Proskuryakov <ap@nypop.com>
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 631 matching lines @@
 
     LayoutRect topLevelRect;
     IntRect paintingRect = pixelSnappedIntRect(renderer->paintingRootRect(topLevelRect));
 
     float deviceScaleFactor = 1;
     if (m_page)
         deviceScaleFactor = m_page->deviceScaleFactor();
     paintingRect.setWidth(paintingRect.width() * deviceScaleFactor);
     paintingRect.setHeight(paintingRect.height() * deviceScaleFactor);
 
-    OwnPtr<ImageBuffer> buffer(ImageBuffer::create(paintingRect.size(), deviceScaleFactor));
+    OwnPtr<ImageBuffer> buffer = ImageBuffer::create(paintingRect.size());
     if (!buffer)
         return nullptr;
+    buffer->context()->scale(FloatSize(deviceScaleFactor, deviceScaleFactor));
     buffer->context()->translate(-paintingRect.x(), -paintingRect.y());
     buffer->context()->clip(FloatRect(0, 0, paintingRect.maxX(), paintingRect.maxY()));
 
     m_view->paintContents(buffer->context(), paintingRect);
 
     RefPtr<Image> image = buffer->copyImage();
     return DragImage::create(image.get(), renderer->shouldRespectImageOrientation());
 }
 
 PassOwnPtr<DragImage> Frame::dragImageForSelection()
 {
     if (!selection().isRange())
         return nullptr;
 
     const ScopedFramePaintingState state(this, 0);
     m_view->setPaintBehavior(PaintBehaviorSelectionOnly | PaintBehaviorFlattenCompositingLayers);
     document()->updateLayout();
 
     IntRect paintingRect = enclosingIntRect(selection().bounds());
 
     float deviceScaleFactor = 1;
     if (m_page)
         deviceScaleFactor = m_page->deviceScaleFactor();
     paintingRect.setWidth(paintingRect.width() * deviceScaleFactor);
     paintingRect.setHeight(paintingRect.height() * deviceScaleFactor);
 
-    OwnPtr<ImageBuffer> buffer(ImageBuffer::create(paintingRect.size(), deviceScaleFactor));
+    OwnPtr<ImageBuffer> buffer = ImageBuffer::create(paintingRect.size());
     if (!buffer)
         return nullptr;
+    buffer->context()->scale(FloatSize(deviceScaleFactor, deviceScaleFactor));
     buffer->context()->translate(-paintingRect.x(), -paintingRect.y());
     buffer->context()->clip(FloatRect(0, 0, paintingRect.maxX(), paintingRect.maxY()));
 
     m_view->paintContents(buffer->context(), paintingRect);
 
     RefPtr<Image> image = buffer->copyImage();
     return DragImage::create(image.get());
 }
 
 double Frame::devicePixelRatio() const
 {
     if (!m_page)
         return 0;
 
     double ratio = m_page->deviceScaleFactor();
     if (RuntimeEnabledFeatures::devicePixelRatioIncludesZoomEnabled())
         ratio *= pageZoomFactor();
     return ratio;
 }
 
 } // namespace WebCore