Avoid duplication of calling getTransformedClipBounds in stroke APIs.

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 1049 matching lines @@
         fullCanvasCompositedStroke(path);
         didDraw(clipBounds);
     } else if (state().m_globalComposite == CompositeCopy) {
         clearCanvas();
         c->strokePath(path);
         didDraw(clipBounds);
     } else {
         FloatRect bounds = path.boundingRect();
         inflateStrokeRect(bounds);
         FloatRect dirtyRect;
-        if (computeDirtyRect(bounds, &dirtyRect)) {
+        if (computeDirtyRect(bounds, clipBounds, &dirtyRect)) {
             c->strokePath(path);
             didDraw(dirtyRect);
         }
     }
 }
 
 void CanvasRenderingContext2D::stroke()
 {
     strokeInternal(m_path);
 }
@@ skipping 247 matching lines @@
         fullCanvasCompositedStroke(rect);
         didDraw(clipBounds);
     } else if (state().m_globalComposite == CompositeCopy) {
         clearCanvas();
         c->strokeRect(rect);
         didDraw(clipBounds);
     } else {
         FloatRect boundingRect = rect;
         boundingRect.inflate(state().m_lineWidth / 2);
         FloatRect dirtyRect;
-        if (computeDirtyRect(boundingRect, &dirtyRect)) {
+        if (computeDirtyRect(boundingRect, clipBounds, &dirtyRect)) {
             c->strokeRect(rect);
             didDraw(dirtyRect);
         }
     }
 }
 
 void CanvasRenderingContext2D::setShadow(float width, float height, float blur)
 {
     setShadow(FloatSize(width, height), blur, Color::transparent);
 }
@@ skipping 1062 matching lines @@
     c->setAlphaAsFloat(1.0);
     c->clearShadow();
     c->setCompositeOperation(CompositeSourceOver, blink::WebBlendModeNormal);
     c->drawFocusRing(path, focusRingWidth, focusRingOutline, focusRingColor);
     c->restore();
 
     didDraw(dirtyRect);
 }
 
 } // namespace WebCore