Implement 'will-change' parsing

Source/core/css/resolver/StyleBuilderCustom.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  * 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.
@@ skipping 846 matching lines @@
 
     unsigned t = 0;
     for (CSSValueListIterator i(value); i.hasMore(); i.advance()) {
         CSSValue* item = i.value();
         TextUnderlinePosition t2 = *toCSSPrimitiveValue(item);
         t |= t2;
     }
     state.style()->setTextUnderlinePosition(static_cast<TextUnderlinePosition>(t));
 }
 
+void StyleBuilderFunctions::applyInitialCSSPropertyWillChange(StyleResolverState& state)
+{
+    state.style()->setWillChangeContents(false);
+    state.style()->setWillChangeScrollPosition(false);
+    state.style()->setWillChangeProperties(Vector<CSSPropertyID>());
+}
+
+void StyleBuilderFunctions::applyInheritCSSPropertyWillChange(StyleResolverState& state)
+{
+    state.style()->setWillChangeContents(state.parentStyle()->willChangeContents());
+    state.style()->setWillChangeScrollPosition(state.parentStyle()->willChangeScrollPosition());
+    state.style()->setWillChangeProperties(state.parentStyle()->willChangeProperties());
+}
+
+void StyleBuilderFunctions::applyValueCSSPropertyWillChange(StyleResolverState& state, CSSValue* value)
+{
+    ASSERT(value->isValueList());
+    bool willChangeContents = false;
+    bool willChangeScrollPosition = false;
+    Vector<CSSPropertyID> willChangeProperties;
+
+    for (CSSValueListIterator i(value); i.hasMore(); i.advance()) {
+        CSSPrimitiveValue* primitiveValue = toCSSPrimitiveValue(i.value());
+        if (CSSPropertyID propertyID = primitiveValue->getPropertyID())
+            willChangeProperties.append(propertyID);
+        else if (primitiveValue->getValueID() == CSSValueContents)
+            willChangeContents = true;
+        else if (primitiveValue->getValueID() == CSSValueScrollPosition)
+            willChangeScrollPosition = true;
+        else
+            ASSERT_NOT_REACHED();
+    }
+    state.style()->setWillChangeContents(willChangeContents);
+    state.style()->setWillChangeScrollPosition(willChangeScrollPosition);
+    state.style()->setWillChangeProperties(willChangeProperties);
+}
+
 // Everything below this line is from the old StyleResolver::applyProperty
 // and eventually needs to move into new StyleBuilderFunctions calls intead.
 
 #define HANDLE_INHERIT(prop, Prop) \
 if (isInherit) { \
     state.style()->set##Prop(state.parentStyle()->prop()); \
     return; \
 }
 
 #define HANDLE_INHERIT_AND_INITIAL(prop, Prop) \
@@ skipping 1060 matching lines @@
     case CSSPropertyWebkitWrapFlow:
     case CSSPropertyShapeMargin:
     case CSSPropertyShapePadding:
     case CSSPropertyShapeImageThreshold:
     case CSSPropertyWebkitWrapThrough:
     case CSSPropertyShapeInside:
     case CSSPropertyShapeOutside:
     case CSSPropertyWhiteSpace:
     case CSSPropertyWidows:
     case CSSPropertyWidth:
+    case CSSPropertyWillChange:
     case CSSPropertyWordBreak:
     case CSSPropertyWordSpacing:
     case CSSPropertyWordWrap:
     case CSSPropertyZIndex:
     case CSSPropertyZoom:
     case CSSPropertyFontFamily:
     case CSSPropertyGridAutoFlow:
     case CSSPropertyMarker:
     case CSSPropertyAlignmentBaseline:
     case CSSPropertyBufferedRendering:
@@ skipping 176 matching lines @@
         break;
     }
     case CSSPropertyEnableBackground:
         // Silently ignoring this property for now
         // http://bugs.webkit.org/show_bug.cgi?id=6022
         break;
     }
 }
 
 } // namespace WebCore