A thread-safe Media Query Parser

Source/core/css/MediaQuery.cpp

Index: Source/core/css/MediaQuery.cpp
diff --git a/Source/core/css/MediaQuery.cpp b/Source/core/css/MediaQuery.cpp
index 681ac137fa2c7c041b64681a6331fba4556ed79e..819c7a185897c7d2302d6ccce47334f65df800a5 100644
--- a/Source/core/css/MediaQuery.cpp
+++ b/Source/core/css/MediaQuery.cpp
@@ -30,11 +30,14 @@
 #include "core/css/MediaQuery.h"
 
 #include "core/css/MediaQueryExp.h"
+#include "core/html/parser/HTMLParserIdioms.h"
 #include "wtf/NonCopyingSort.h"
 #include "wtf/text/StringBuilder.h"
 
 namespace WebCore {
 
+// FIXME - need to add common keywords (e.g. all, only, none, and) to static strings
+
 // http://dev.w3.org/csswg/cssom/#serialize-a-media-query
 String MediaQuery::serialize() const
 {
@@ -73,11 +76,16 @@ static bool expressionCompare(const OwnPtr<MediaQueryExp>& a, const OwnPtr<Media
     return codePointCompare(a->serialize(), b->serialize()) < 0;
 }
 
-MediaQuery::MediaQuery(Restrictor r, const AtomicString& mediaType, PassOwnPtr<ExpressionVector> expressions)
+MediaQuery::MediaQuery(Restrictor r, const String& mediaType, PassOwnPtr<ExpressionVector> expressions)
     : m_restrictor(r)
-    , m_mediaType(mediaType.lower())
     , m_expressions(expressions)
 {
+    if (mediaType.impl()) {
+        String lowerMediaType = String(mediaType.lower());
+        lowerMediaType.ensure16Bit();
+        m_mediaType = attemptStaticStringCreation(lowerMediaType, Force16Bit);

[abarth-chromium, 2014/03/01 07:28:25]

Then you won't need this sort of thing.

+    }
+
     if (!m_expressions) {
         m_expressions = adoptPtr(new ExpressionVector);
         return;
@@ -99,7 +107,7 @@ MediaQuery::MediaQuery(Restrictor r, const AtomicString& mediaType, PassOwnPtr<E
 
 MediaQuery::MediaQuery(const MediaQuery& o)
     : m_restrictor(o.m_restrictor)
-    , m_mediaType(o.m_mediaType)
+    , m_mediaType(o.m_mediaType.impl())
     , m_expressions(adoptPtr(new ExpressionVector(o.m_expressions->size())))
     , m_serializationCache(o.m_serializationCache)
 {