Fix the double-tap to click gesture in touch accessibility mode.

chrome/common/extensions/api/accessibility_private.json

 // 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.
 
 [
   {
     "namespace": "accessibilityPrivate",
     "compiler_options": {
       "implemented_in": "chrome/browser/accessibility/accessibility_extension_api.h"
     },
@@ skipping 17 matching lines @@
         "properties": {
           "left": {"type": "integer", "description": "Left coordinate in global screen coordinates."},
           "top": {"type": "integer", "description": "Top coordinate in global screen coordinates."},
           "width": {"type": "integer", "description": "Width in pixels."},
           "height": {"type": "integer", "description": "Height in pixels."}
         }
       },
       {
         "id": "Gesture",
         "type": "string",
-        "enum": [ "doubleTap", "swipeLeft1", "swipeUp1", "swipeRight1", "swipeDown1", "swipeLeft2", "swipeUp2", "swipeRight2", "swipeDown2", "swipeLeft3", "swipeUp3", "swipeRight3", "swipeDown3", "swipeLeft4", "swipeUp4", "swipeRight4", "swipeDown4" ],
+        "enum": [ "click", "swipeLeft1", "swipeUp1", "swipeRight1", "swipeDown1", "swipeLeft2", "swipeUp2", "swipeRight2", "swipeDown2", "swipeLeft3", "swipeUp3", "swipeRight3", "swipeDown3", "swipeLeft4", "swipeUp4", "swipeRight4", "swipeDown4" ],
         "description": "Accessibility gestures fired by the touch exploration controller."
       }
     ],
     "functions": [
       {
         "name": "setNativeAccessibilityEnabled",
         "type": "function",
         "description": "Enables or disables native accessibility support. Once disabled, it is up to the calling extension to provide accessibility for web contents.",
         "parameters": [
           {
@@ skipping 48 matching lines @@
         "parameters": [
           {
             "name": "gesture",
             "$ref": "Gesture"
           }
         ]
       }
     ]
   }
 ]