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

third_party/WebKit/Source/core/editing/InputMethodController.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 420 matching lines @@
   if (frame().selection().isNone())
     return;
 
   clear();
 
   // TODO(chongz): Figure out which InputType should we use here.
   dispatchBeforeInputFromComposition(
       document().focusedElement(),
       InputEvent::InputType::DeleteComposedCharacterBackward, nullAtom,
       InputEvent::EventCancelable::NotCancelable);
-  dispatchCompositionUpdateEvent(frame(), emptyString());
+  dispatchCompositionUpdateEvent(frame(), emptyString);
   insertTextDuringCompositionWithEvents(
-      frame(), emptyString(), 0,
+      frame(), emptyString, 0,
       TypingCommand::TextCompositionType::TextCompositionCancel);
   // Event handler might destroy document.
   if (!isAvailable())
     return;
 
   // An open typing command that disagrees about current selection would cause
   // issues with typing later on.
   TypingCommand::closeTyping(m_frame);
 
   // No DOM update after 'compositionend'.
-  dispatchCompositionEndEvent(frame(), emptyString());
+  dispatchCompositionEndEvent(frame(), emptyString);
 }
 
 void InputMethodController::cancelCompositionIfSelectionIsInvalid() {
   if (!hasComposition() || editor().preventRevealSelection())
     return;
 
   // Check if selection start and selection end are valid.
   FrameSelection& selection = frame().selection();
   if (!selection.isNone() && !m_compositionRange->collapsed()) {
     if (selection.start().compareTo(m_compositionRange->startPosition()) >= 0 &&
@@ skipping 70 matching lines @@
   //    compositionupdate event is dispatched.
   // 2. Updating the existing composition node.
   //    Send a compositionupdate event when this function updates the existing
   //    composition node, i.e. hasComposition() && !text.isEmpty().
   // 3. Canceling the ongoing composition.
   //    Send a compositionend event when function deletes the existing
   //    composition node, i.e. !hasComposition() && test.isEmpty().
   if (text.isEmpty()) {
     if (hasComposition()) {
       Editor::RevealSelectionScope revealSelectionScope(&editor());
-      replaceComposition(emptyString());
+      replaceComposition(emptyString);
     } else {
       // It's weird to call |setComposition()| with empty text outside
       // composition, however some IME (e.g. Japanese IBus-Anthy) did this, so
       // we simply delete selection without sending extra events.
       TypingCommand::deleteSelection(document(),
                                      TypingCommand::PreventSpellChecking);
     }
 
     // TODO(xiaochengh): The use of updateStyleAndLayoutIgnorePendingStylesheets
     // needs to be audited. see http://crbug.com/590369 for more details.
@@ skipping 535 matching lines @@
   frame().chromeClient().resetInputMethod();
 }
 
 DEFINE_TRACE(InputMethodController) {
   visitor->trace(m_frame);
   visitor->trace(m_compositionRange);
   SynchronousMutationObserver::trace(visitor);
 }
 
 }  // namespace blink