[cros] RLZ tracking can be turned off via a flag file.

build/common.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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 1431 matching lines @@
         'win_release_InlineFunctionExpansion': '1',
         'win_release_OmitFramePointers': '0',
         # Ditto for debug, to support bumping win_debug_Optimization.
         'win_debug_InlineFunctionExpansion': 0,
         'win_debug_OmitFramePointers': 0,
         # Keep the code under #ifndef NVALGRIND.
         'release_valgrind_build': 1,
       }],
 
       # Enable RLZ on Win, Mac and ChromeOS.
-      ['branding=="Chrome" and (OS=="win" or OS=="mac" or chromeos==1)', {

[Ivan Korotkov, 2012/12/11 10:53:19]

For trybots

+      ['(OS=="win" or OS=="mac" or chromeos==1)', {
         'enable_rlz%': 1,
       }],
     ],
 
     # List of default apps to install in new profiles.  The first list contains
     # the source files as found in svn.  The second list, used only for linux,
     # contains the destination location for each of the files.  When a crx
     # is added or removed from the list, the chrome/browser/resources/
     # default_apps/external_extensions.json file must also be updated.
     'default_apps_list': [
@@ skipping 2458 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }