Add a --enable-gesture-typing flag. Currently this flag does nothing.

ui/keyboard/resources/keyboard_mojo.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 var connection;
 var mojo_api;
 var input_focused_event;
 
 if (!chrome.virtualKeyboardPrivate) {
   define('main', [
       'mojo/public/js/connection',
@@ skipping 42 matching lines @@
       return;
     mojo_api.keyboard_.hideKeyboard();
   };
   chrome.virtualKeyboardPrivate.moveCursor = function() {};
   chrome.virtualKeyboardPrivate.lockKeyboard = function() {};
   chrome.virtualKeyboardPrivate.keyboardLoaded = function() {};
   chrome.virtualKeyboardPrivate.getKeyboardConfig = function(callback) {
     callback({
       layout: 'qwerty',
       a11ymode: false,
-      experimental: false
+      experimental: false,
+      gesturetyping: false
     });
   };
 
   function BrowserEvent() {
     this.listeners_ = [];
   };
 
   BrowserEvent.prototype.addListener = function(callback) {
     this.listeners_.push(callback);
   };
 
   BrowserEvent.prototype.forEach = function(callback) {
     for (var i = 0; i < this.listeners_.length; ++i)
       callback(this.listeners_[i]);
   };
 
   input_focused_event = new BrowserEvent;
   chrome.virtualKeyboardPrivate.onTextInputBoxFocused = input_focused_event;
 }