General code cleanup of ChromeClient-related classes.

Source/core/svg/graphics/SVGImageChromeClient.cpp

 /*
  * Copyright (C) 2012 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
@@ skipping 34 matching lines @@
 {
 }
 
 bool SVGImageChromeClient::isSVGImageChromeClient() const
 {
     return true;
 }
 
 void SVGImageChromeClient::chromeDestroyed()
 {
-    m_image = 0;
+    m_image = nullptr;
 }
 
 void SVGImageChromeClient::invalidateRect(const IntRect& r)
 {
     // If m_image->m_page is null, we're being destructed, don't fire changedInRect() in that case.
     if (m_image && m_image->imageObserver() && m_image->m_page)
         m_image->imageObserver()->changedInRect(m_image, r);
 }
 
 void SVGImageChromeClient::scheduleAnimation()
@@ skipping 32 matching lines @@
     // object protection isn't made the conditional on Oilpan.
     //
     // FIXME: Oilpan: move this and other ChromeClients to the Oilpan heap
     // to render this protection redundant.
     RefPtr<SVGImage> protect(m_image);
     m_image->frameView()->page()->animator().serviceScriptedAnimations(monotonicallyIncreasingTime());
     m_image->frameView()->updateLayoutAndStyleForPainting();
 }
 
 } // namespace blink