Make Element::ensureActiveAnimations() return a reference

Source/core/css/resolver/StyleResolver.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 75 matching lines @@
 
 namespace {
 
 using namespace WebCore;
 
 void setAnimationUpdateIfNeeded(StyleResolverState& state, Element& element)
 {
     // If any changes to CSS Animations were detected, stash the update away for application after the
     // render object is updated if we're in the appropriate scope.
     if (state.animationUpdate())
-        element.ensureActiveAnimations()->cssAnimations().setPendingUpdate(state.takeAnimationUpdate());
+        element.ensureActiveAnimations().cssAnimations().setPendingUpdate(state.takeAnimationUpdate());
 }
 
 } // namespace
 
 namespace WebCore {
 
 using namespace HTMLNames;
 
 RenderStyle* StyleResolver::s_styleNotYetAvailable;
 
@@ skipping 1304 matching lines @@
 bool StyleResolver::mediaQueryAffectedByViewportChange() const
 {
     for (unsigned i = 0; i < m_viewportDependentMediaQueryResults.size(); ++i) {
         if (m_medium->eval(&m_viewportDependentMediaQueryResults[i]->m_expression) != m_viewportDependentMediaQueryResults[i]->m_result)
             return true;
     }
     return false;
 }
 
 } // namespace WebCore