Replace WTF::emptyString{16Bit}() with a static global

third_party/WebKit/Source/core/dom/DOMURLUtilsReadOnly.cpp

Index: third_party/WebKit/Source/core/dom/DOMURLUtilsReadOnly.cpp
diff --git a/third_party/WebKit/Source/core/dom/DOMURLUtilsReadOnly.cpp b/third_party/WebKit/Source/core/dom/DOMURLUtilsReadOnly.cpp
index a2cbc2a3b1cf530ebbd0be96eb5a0740d4bf0be7..0c6fe5a7de125d6457aeb7b24e6e12b8741db8fb 100644
--- a/third_party/WebKit/Source/core/dom/DOMURLUtilsReadOnly.cpp
+++ b/third_party/WebKit/Source/core/dom/DOMURLUtilsReadOnly.cpp
@@ -56,18 +56,18 @@ String DOMURLUtilsReadOnly::port(const KURL& kurl) {
   if (kurl.hasPort())
     return String::number(kurl.port());
 
-  return emptyString();
+  return emptyString;
 }
 
 String DOMURLUtilsReadOnly::search(const KURL& kurl) {
   String query = kurl.query();
-  return query.isEmpty() ? emptyString() : "?" + query;
+  return query.isEmpty() ? emptyString : "?" + query;
 }
 
 String DOMURLUtilsReadOnly::hash(const KURL& kurl) {
   String fragmentIdentifier = kurl.fragmentIdentifier();
   if (fragmentIdentifier.isEmpty())
-    return emptyString();
+    return emptyString;
   return AtomicString(String("#" + fragmentIdentifier));
 }