[Extensions] Remove unused parts of the preferencesPrivate API

chrome/common/extensions/api/preferences_private.json

 // Copyright 2013 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": "preferencesPrivate",
     "description": "none",
     "properties": {
       "easyUnlockProximityRequired": {
         "nocompile": true,
         "$ref": "types.private.ChromeDirectSetting",
         "value": ["easy_unlock.proximity_required", {"type":"boolean"}],
         "description": "If true, a remote Easy Unlock device can only unlock the local device if it is in very close proximity (roughly, within a foot). This preference's value is a boolean, defaulting to <code>false</code>."
-      },
-      "googleGeolocationAccessEnabled": {
-        "nocompile": true,
-        "$ref": "types.private.ChromeDirectSetting",
-        "value": ["googlegeolocationaccess.enabled", {"type":"boolean"}],

[asargent_no_longer_on_chrome, 2016/03/09 23:07:44]

I think you also want to remove "googlegeolocationaccess.enabled" from
PreferenceWhitelist in
chrome/browser/extensions/api/preference/chrome_direct_setting_api.cc

(I happened to run across this file because I was trying to understand how the
heck these property read/writes work, and finally went back to the CL adding
easyUnlockProximityRequired and noticed it being added there). 

[Devlin, 2016/03/10 19:08:41]

Good call!  It also looks like that was the only time we used that pref, so we
can remove it entirely. Do you recall if we have to push out a pref deletion
before just removing the entry here or if the service knows to delete any
unknown prefs?

-        "description": "If enabled, Google services can access the user's location. This preference's value is a boolean, defaulting to <code>false</code>."
       }
-    },
-    "functions": [
-      {
-        "name": "getSyncCategoriesWithoutPassphrase",
-        "description": "Returns a list of sync categories the user has enabled without using a custom passphrase for encryption. The possible values are those that can be returned from syncer::ModelTypeToString in sync/syncable/model_type.cc.",
-        "type": "function",
-        "parameters": [
-          {
-            "name": "callback",
-            "type": "function",
-            "parameters": [
-              {
-                "name": "categories",
-                "type": "array",
-                "items": {"type": "string"}
-              }
-            ]
-          }
-        ]
-      }
-    ]
+    }
   }
 ]