clang: Uncomment new warning flag.

build/common.gypi

 # Copyright (c) 2011 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 1345 matching lines @@
                 ],
               }]],
           }],
           ['clang==1 and chromeos==1', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags': [
                   # TODO(thakis): Remove this once all instances of this
                   # are fixed in the views and chromeos code.
                   # http://crbug.com/84424
-                  '-Wno-delete-non-virtual-dtor',
+                  # TODO(thakis): Add back in when rolling clang past r131989
+                  #'-Wno-delete-non-virtual-dtor',
                 ],
               }]],
           }],
           ['clang==1 and clang_use_chrome_plugins==1', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags': [
                   '<(clang_chrome_plugins_flags)',
                 ],
               }]],
@@ skipping 398 matching lines @@
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: