Add support for the object-fit CSS property.

Source/core/rendering/RenderHTMLCanvas.cpp

 /*
  * Copyright (C) 2004, 2006, 2007 Apple 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:
  * 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 37 matching lines @@
 {
     if (RenderReplaced::requiresLayer())
         return true;
 
     HTMLCanvasElement* canvas = toHTMLCanvasElement(node());
     return canvas && canvas->renderingContext() && canvas->renderingContext()->isAccelerated();
 }
 
 void RenderHTMLCanvas::paintReplaced(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
-    LayoutRect rect = contentBoxRect();
-    rect.moveBy(paintOffset);
+    GraphicsContext* context = paintInfo.context;
+
+    LayoutRect contentRect = contentBoxRect();
+    contentRect.moveBy(paintOffset);
+    LayoutRect paintRect = replacedContentRect();
+    paintRect.moveBy(paintOffset);
+
+    bool clip = !contentRect.contains(paintRect);
+    if (clip) {
+        // Not allowed to overflow the content box.
+        paintInfo.context->save();
+        paintInfo.context->clip(pixelSnappedIntRect(contentRect));
+    }
 
     if (Frame* frame = this->frame()) {
         if (Page* page = frame->page()) {
             if (paintInfo.phase == PaintPhaseForeground)
-                page->addRelevantRepaintedObject(this, rect);
+                page->addRelevantRepaintedObject(this, intersection(paintRect, contentRect));
         }
     }
 
     bool useLowQualityScale = style()->imageRendering() == ImageRenderingOptimizeContrast;
-    toHTMLCanvasElement(node())->paint(paintInfo.context, rect, useLowQualityScale);
+    toHTMLCanvasElement(node())->paint(context, paintRect, useLowQualityScale);
+
+    if (clip)
+        context->restore();
 }
 
 void RenderHTMLCanvas::canvasSizeChanged()
 {
     IntSize canvasSize = toHTMLCanvasElement(node())->size();
     LayoutSize zoomedSize(canvasSize.width() * style()->effectiveZoom(), canvasSize.height() * style()->effectiveZoom());
 
     if (zoomedSize == intrinsicSize())
         return;
 
     setIntrinsicSize(zoomedSize);
 
     if (!parent())
         return;
 
     if (!preferredLogicalWidthsDirty())
         setPreferredLogicalWidthsDirty(true);
 
     LayoutSize oldSize = size();
     updateLogicalWidth();
     updateLogicalHeight();
     if (oldSize == size())
         return;
 
     if (!selfNeedsLayout())
         setNeedsLayout(true);
 }
 
 } // namespace WebCore