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

Source/core/loader/FormSubmission.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 50 matching lines @@
         }
 
         Method method() const { return m_method; }
         static Method parseMethodType(const String&);
         void updateMethodType(const String&);
         static String methodString(Method);
 
         const String& action() const { return m_action; }
         void parseAction(const String&);
 
-        const String& target() const { return m_target; }
-        void setTarget(const String& target) { m_target = target; }
+        const AtomicString& target() const { return m_target; }
+        void setTarget(const AtomicString& target) { m_target = target; }
 
         const String& encodingType() const { return m_encodingType; }
         static String parseEncodingType(const String&);
         void updateEncodingType(const String&);
         bool isMultiPartForm() const { return m_isMultiPartForm; }
 
         const String& acceptCharset() const { return m_acceptCharset; }
         void setAcceptCharset(const String& value) { m_acceptCharset = value; }
 
         void copyFrom(const Attributes&);
 
     private:
         Method m_method;
         bool m_isMultiPartForm;
 
         String m_action;
-        String m_target;
+        AtomicString m_target;
         String m_encodingType;
         String m_acceptCharset;
     };
 
     static PassRefPtr<FormSubmission> create(HTMLFormElement*, const Attributes&, PassRefPtr<Event> event, FormSubmissionTrigger);
 
     void populateFrameLoadRequest(FrameLoadRequest&);
 
     KURL requestURL() const;
 
     Method method() const { return m_method; }
     const KURL& action() const { return m_action; }
-    const String& target() const { return m_target; }
-    void clearTarget() { m_target = String(); }
+    const AtomicString& target() const { return m_target; }
+    void clearTarget() { m_target = nullAtom; }
     const String& contentType() const { return m_contentType; }
     FormState* state() const { return m_formState.get(); }
     FormData* data() const { return m_formData.get(); }
     const String boundary() const { return m_boundary; }
     Event* event() const { return m_event.get(); }
 
     const String& referrer() const { return m_referrer; }
     void setReferrer(const String& referrer) { m_referrer = referrer; }
     const String& origin() const { return m_origin; }
     void setOrigin(const String& origin) { m_origin = origin; }
 
     const String& result() const { return m_result; }
 
 private:
-    FormSubmission(Method, const KURL& action, const String& target, const String& contentType, PassRefPtr<FormState>, PassRefPtr<FormData>, const String& boundary, PassRefPtr<Event>);
+    FormSubmission(Method, const KURL& action, const AtomicString& target, const String& contentType, PassRefPtr<FormState>, PassRefPtr<FormData>, const String& boundary, PassRefPtr<Event>);
     // FormSubmission for DialogMethod
     FormSubmission(const String& result);
 
     // FIXME: Hold an instance of Attributes instead of individual members.
     Method m_method;
     KURL m_action;
-    String m_target;
+    AtomicString m_target;
     String m_contentType;
     RefPtr<FormState> m_formState;
     RefPtr<FormData> m_formData;
     String m_boundary;
     RefPtr<Event> m_event;
     String m_referrer;
     String m_origin;
     String m_result;
 };
 
 }
 
 #endif // FormSubmission_h