Make calls to AtomicString(const String&) explicit in css/

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 16f08b1d4c9824b2eb7d421e322eda7230746e85..681ac137fa2c7c041b64681a6331fba4556ed79e 100644
--- a/Source/core/css/MediaQuery.cpp
+++ b/Source/core/css/MediaQuery.cpp
@@ -73,7 +73,7 @@ static bool expressionCompare(const OwnPtr<MediaQueryExp>& a, const OwnPtr<Media
     return codePointCompare(a->serialize(), b->serialize()) < 0;
 }
 
-MediaQuery::MediaQuery(Restrictor r, const String& mediaType, PassOwnPtr<ExpressionVector> expressions)
+MediaQuery::MediaQuery(Restrictor r, const AtomicString& mediaType, PassOwnPtr<ExpressionVector> expressions)
     : m_restrictor(r)
     , m_mediaType(mediaType.lower())
     , m_expressions(expressions)