Add enable_automation build switch.

chrome/chrome_browser.gypi

 # Copyright (c) 2012 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.
 
 {
   'targets': [
     {
       'target_name': 'browser',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
@@ skipping 4428 matching lines @@
           'sources/': [
             ['exclude', '^browser/notifications/'],
           ],
         }],
         ['enable_web_intents==0', {
           'sources/': [
             ['exclude', '^browser/intents'],
             ['exclude', '^browser/ui/intents'],
           ],
         }],
+        ['enable_automation!=1', {
+          'sources/': [
+            ['exclude', '^browser/automation/'],
+          ],
+        }],
         ['OS=="android"', {
           'sources!': [
             'browser/bookmarks/bookmark_context_menu_controller.cc',
             # Bookmark export/import are handled via the BookmarkColumns
             # ContentProvider.
             'browser/bookmarks/bookmark_html_writer.cc',
             'browser/jankometer.cc',
             'browser/ui/sad_tab_helper.cc',
             'browser/ui/sync/one_click_signin_dialog.h',
             'browser/ui/sync/one_click_signin_helper.cc',
@@ skipping 904 matching lines @@
          'variables': {
           'proto_in_dir': '../third_party/cros_system_api/dbus/',
           'proto_out_dir': 'chrome/browser/chromeos/dbus',
          },
          'includes': ['../build/protoc.gypi'],
         }],
       ],
     },
   ],
 }