Make touch accessibility gestures work with ChromeVox Next

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 13 matching lines @@
       {
         "id": "ScreenRect",
         "type": "object",
         "description": "Bounding rectangle in global screen coordinates.",
         "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" ],
+        "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": [
           {
             "type": "boolean",
@@ skipping 20 matching lines @@
         "type": "function",
         "description": "Sets the calling extension as a listener of all keyboard events optionally allowing the calling extension to capture/swallow the key event via DOM apis. Returns false via callback when unable to set the listener.",
         "parameters": [
           {
             "type": "boolean",
             "name": "enabled",
             "description": "True if the caller wants to listen to key events; false to stop listening to events. Note that there is only ever one extension listening to key events."
           },
           {
             "type": "boolean",
+
             "name": "capture",
             "description": "True if key events should be swallowed natively and not propagated if preventDefault() gets called by the extension's background page."
           }
         ]
       }
     ],
     "events": [
       {
         "name": "onIntroduceChromeVox",
         "type": "function",
         "description": "Fired whenever ChromeVox should output introduction."
+      },
+      {
+        "name": "onAccessibilityGesture",
+        "type": "function",
+        "description": "Fired when an accessibility gesture is detected by the touch exploration controller.",
+        "parameters": [
+          {
+            "name": "gesture",
+            "$ref": "Gesture"
+          }
+        ]
       }
     ]
   }
 ]