[Chromoting] Add ability to enable/disable GDrive support per-app in gyp.

remoting/app_remoting_webapp_build.gypi

 # 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.
 
 {
   'includes': [
     'remoting_version.gypi',
     'remoting_locales.gypi',
     'remoting_webapp_files.gypi',
     'app_remoting_webapp_files.gypi',
@@ skipping 104 matching lines @@
           '<@(ar_generated_html_files)',
           '--locales',
           '<@(remoting_webapp_locale_files)',
           '--jinja_paths',
           '<(DEPTH)/remoting/webapp/app_remoting',
           '<@(remoting_app_id)',
           '--app_name',
           '<(remoting_app_name)',
           '--app_description',
           '<(remoting_app_description)',
+          '--app_capabilities',
+          '>@(_app_capabilities)',
           '--service_environment',
           '<@(ar_service_environment)',
         ],
       },
       {
         'action_name': 'Build ">(ar_app_name)" main.html',
         'inputs': [
           '<(DEPTH)/remoting/webapp/build-html.py',
           '<(ar_main_template)',
           '<@(ar_main_template_files)',
@@ skipping 42 matching lines @@
         # rather than using the extension id.
         # This is only done for Dev apps because the app-id for Release apps
         # *must* match the extension id.
         'variables': {
           'remoting_app_id': ['--appid', '>(_app_id)'],
         },
       }],
     ],  # conditions
   },  # target_defaults
 }