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

Source/wtf/BitArray.h

Index: Source/wtf/BitArray.h
diff --git a/Source/wtf/BitArray.h b/Source/wtf/BitArray.h
index f1095150619cbfc883317af20f6deb9312ced487..54b84b46d37a682021e525779dedf0bdf8ab774a 100644
--- a/Source/wtf/BitArray.h
+++ b/Source/wtf/BitArray.h
@@ -34,9 +34,9 @@ namespace WTF {
 template<unsigned arraySize>
 class BitArray {
 public:
-    BitArray()
+    BitArray(bool value = false)
     {
-        memset(m_data, 0, sizeof(m_data));
+        memset(m_data, value ? 0xFF : 0, sizeof(m_data));
     }
 
     void set(unsigned index)
@@ -45,6 +45,12 @@ public:
         m_data[index / 8] |= 1 << (index & 7);
     }
 
+    void clear(unsigned index)
+    {
+        ASSERT_WITH_SECURITY_IMPLICATION(index < arraySize);
+        m_data[index / 8] &= ~(1 << (index & 7));
+    }
+
     bool get(unsigned index) const
     {
         ASSERT_WITH_SECURITY_IMPLICATION(index < arraySize);