HTML5 Canvas should avoid converting rotation angle to degrees

Source/core/html/canvas/CanvasRenderingContext2D.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  * Copyright (C) 2012, 2013 Intel Corporation. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
  *
@@ skipping 610 matching lines @@
     GraphicsContext* c = drawingContext();
     if (!c)
         return;
     if (!state().m_invertibleCTM)
         return;
 
     if (!std::isfinite(angleInRadians))
         return;
 
     AffineTransform newTransform = state().m_transform;
-    newTransform.rotate(angleInRadians / piDouble * 180.0);
+    newTransform.rotateRadians(angleInRadians);
     if (state().m_transform == newTransform)
         return;
 
     realizeSaves();
 
     if (!newTransform.isInvertible()) {
         modifiableState().m_invertibleCTM = false;
         return;
     }
 
     modifiableState().m_transform = newTransform;
     c->rotate(angleInRadians);
-    m_path.transform(AffineTransform().rotate(-angleInRadians / piDouble * 180.0));
+    m_path.transform(AffineTransform().rotateRadians(-angleInRadians));
 }
 
 void CanvasRenderingContext2D::translate(float tx, float ty)
 {
     GraphicsContext* c = drawingContext();
     if (!c)
         return;
     if (!state().m_invertibleCTM)
         return;
 
@@ skipping 1645 matching lines @@
     const int focusRingWidth = 5;
     const int focusRingOutline = 0;
     c->drawFocusRing(path, focusRingWidth, focusRingOutline, focusRingColor);
 
     c->restore();
 
     didDraw(dirtyRect);
 }
 
 } // namespace WebCore