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

Source/core/dom/DOMTokenList.h

Index: Source/core/dom/DOMTokenList.h
diff --git a/Source/core/dom/DOMTokenList.h b/Source/core/dom/DOMTokenList.h
index d758214d09a94386619bc627fddf7387ee138010..bdaf34de64418a2ed14dd49cf2883851a2eff5f5 100644
--- a/Source/core/dom/DOMTokenList.h
+++ b/Source/core/dom/DOMTokenList.h
@@ -69,12 +69,12 @@ protected:
     virtual bool containsInternal(const AtomicString&) const = 0;
     virtual void removeInternal(const AtomicString&);
 
-    static bool validateToken(const AtomicString&, ExceptionState&);
+    static bool validateToken(const String&, ExceptionState&);
     static bool validateTokens(const Vector<String>&, ExceptionState&);
-    static String addToken(const AtomicString&, const AtomicString&);
-    static String addTokens(const AtomicString&, const Vector<String>&);
-    static String removeToken(const AtomicString&, const AtomicString&);
-    static String removeTokens(const AtomicString&, const Vector<String>&);
+    static AtomicString addToken(const AtomicString&, const AtomicString&);

[eseidel, 2013/12/15 16:51:26]

Why are these atomic?

[Inactive, 2013/12/16 14:26:27]

Because all the callers expect an AtomicString. The returned value is always
passed to DOMTokenList::setValue(const AtomicString&) defined above (see
DOMTokenList.cpp).

These methods use a StringBuilder internally so they can easily generate either
a String or an AtomicString. Since all callers expect an AtomicString, it is
more efficient to construct directly an AtomicString.

[eseidel, 2013/12/30 17:19:27]

You should add comments whenever you're changing these to explain why various
lasses use Atmic vs. Stirng and if they should IYO.

+    static AtomicString addTokens(const AtomicString&, const Vector<String>&);
+    static AtomicString removeToken(const AtomicString&, const AtomicString&);
+    static AtomicString removeTokens(const AtomicString&, const Vector<String>&);
 };
 
 } // namespace WebCore