Use a BitArray in RuntimeCSSEnabled instead of a Vector<bool>

Source/core/css/RuntimeCSSEnabled.cpp

 /*
  * Copyright (C) 2013 Adobe Systems Incorporated. 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.
@@ skipping 13 matching lines @@
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/css/RuntimeCSSEnabled.h"
 
 #include "RuntimeEnabledFeatures.h"
+#include "wtf/BitArray.h"
 
 namespace WebCore {
 
-// FIXME: We should use a real BitVector class instead!
-typedef Vector<bool> BoolVector;
+typedef BitArray<numCSSProperties> CSSPropertySwitches;
 
 static void setCSSPropertiesEnabled(CSSPropertyID* properties, size_t length, bool featureFlag)
 {
     for (size_t i = 0; i < length; i++)
         RuntimeCSSEnabled::setCSSPropertyEnabled(properties[i], featureFlag);
 }
 
 static void setPropertySwitchesFromRuntimeFeatures()
 {
     CSSPropertyID exclusionProperties[] = {
@@ skipping 74 matching lines @@
     RuntimeCSSEnabled::setCSSPropertyEnabled(CSSPropertyPaintOrder, RuntimeEnabledFeatures::svgPaintOrderEnabled());
     RuntimeCSSEnabled::setCSSPropertyEnabled(CSSPropertyMaskSourceType, RuntimeEnabledFeatures::cssMaskSourceTypeEnabled());
     RuntimeCSSEnabled::setCSSPropertyEnabled(CSSPropertyColumnFill, RuntimeEnabledFeatures::regionBasedColumnsEnabled());
     RuntimeCSSEnabled::setCSSPropertyEnabled(CSSPropertyScrollBehavior, RuntimeEnabledFeatures::cssomSmoothScrollEnabled());
     RuntimeCSSEnabled::setCSSPropertyEnabled(CSSPropertyWillChange, RuntimeEnabledFeatures::cssWillChangeEnabled());
 
     // InternalCallback is an implementation detail, rather than an experimental feature, and should never be exposed to the web.
     RuntimeCSSEnabled::setCSSPropertyEnabled(CSSPropertyInternalCallback, false);
 }
 
-static BoolVector& propertySwitches()
+static CSSPropertySwitches& propertySwitches()
 {
-    static BoolVector* switches = 0;
+    static CSSPropertySwitches* switches = 0;
     if (!switches) {
-        switches = new BoolVector;
-        switches->fill(true, numCSSProperties);
+        switches = new CSSPropertySwitches(true); // All bits sets to 1.
         setPropertySwitchesFromRuntimeFeatures();
     }
     return *switches;
 }
 
 size_t indexForProperty(CSSPropertyID propertyId)
 {
     RELEASE_ASSERT(propertyId >= firstCSSProperty && propertyId <= lastCSSProperty);
-    // Values all start at 0. Vector RELEASE_ASSERTS will catch if we're ever wrong.
+    // Values all start at 0. BitArray ASSERTS will catch if we're ever wrong.
     return static_cast<size_t>(propertyId - firstCSSProperty);
 }
 
 bool RuntimeCSSEnabled::isCSSPropertyEnabled(CSSPropertyID propertyId)
 {
     // Internal properties shouldn't be exposed to the web
     // so they are considered to be always disabled.
     if (isInternalProperty(propertyId))
         return false;
 
-    return propertySwitches()[indexForProperty(propertyId)];
+    return propertySwitches().get(indexForProperty(propertyId));
 }
 
 void RuntimeCSSEnabled::setCSSPropertyEnabled(CSSPropertyID propertyId, bool enable)
 {
-    propertySwitches()[indexForProperty(propertyId)] = enable;
+    size_t propertyIndex = indexForProperty(propertyId);
+    if (enable)
+        propertySwitches().set(propertyIndex);
+    else
+        propertySwitches().clear(propertyIndex);
 }
 
 void RuntimeCSSEnabled::filterEnabledCSSPropertiesIntoVector(const CSSPropertyID* properties, size_t propertyCount, Vector<CSSPropertyID>& outVector)
 {
     for (unsigned i = 0; i < propertyCount; i++) {
         CSSPropertyID property = properties[i];
         if (RuntimeCSSEnabled::isCSSPropertyEnabled(property))
             outVector.append(property);
     }
 }
 
 } // namespace WebCore