Don't pixel-snap box size before applying transform to it.

third_party/WebKit/Source/core/paint/PaintLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 375 matching lines @@
                          !child->isPaintInvalidationContainer());
   }
 }
 
 void PaintLayer::updateTransformationMatrix() {
   if (TransformationMatrix* transform = this->transform()) {
     LayoutBox* box = layoutBox();
     ASSERT(box);
     transform->makeIdentity();
     box->style()->applyTransform(
-        *transform, LayoutSize(box->pixelSnappedSize()),
-        ComputedStyle::IncludeTransformOrigin, ComputedStyle::IncludeMotionPath,
+        *transform, box->size(), ComputedStyle::IncludeTransformOrigin,
+        ComputedStyle::IncludeMotionPath,
         ComputedStyle::IncludeIndependentTransformProperties);
     makeMatrixRenderable(*transform, compositor()->hasAcceleratedCompositing());
   }
 }
 
 void PaintLayer::updateTransform(const ComputedStyle* oldStyle,
                                  const ComputedStyle& newStyle) {
   if (oldStyle && newStyle.transformDataEquivalent(*oldStyle))
     return;
 
@@ skipping 2799 matching lines @@
 }
 
 void showLayerTree(const blink::LayoutObject* layoutObject) {
   if (!layoutObject) {
     fprintf(stderr, "Cannot showLayerTree. Root is (nil)\n");
     return;
   }
   showLayerTree(layoutObject->enclosingLayer());
 }
 #endif