Removed -Wno-overloaded-virtual warning suppression.

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 3069 matching lines @@
         'defines': ['USE_NSS_CERTS=1'],
       }],
       ['<(chromeos)==1 and >(nacl_untrusted_build)==0', {
         'defines': ['OS_CHROMEOS=1'],
       }],
       ['enable_wexit_time_destructors==1 and OS!="win"', {
         # TODO: Enable on Windows too, http://crbug.com/404525
         'variables': { 'clang_warning_flags': ['-Wexit-time-destructors']},
       }],
       ['chromium_code==0', {
+        'variables': {
+          'clang_warning_flags': [
+            # TODO(mgiuca): Move this suppression into individual third-party
+            # libraries as required. http://crbug.com/505301.
+            '-Wno-overloaded-virtual',
+          ],
+        },
         'conditions': [
           [ 'os_posix==1 and OS!="mac" and OS!="ios"', {
             # We don't want to get warnings from third-party code,
             # so remove any existing warning-enabling flags like -Wall.
             'cflags!': [
               '-Wall',
               '-Wextra',
             ],
             'cflags_cc': [
               # Don't warn about hash_map in third-party code.
@@ skipping 2600 matching lines @@
 
                   # TODO(hans): Make this list shorter eventually, http://crbug.com/504657
                   '-Qunused-arguments',  # http://crbug.com/504658
                   '-Wno-empty-body',  # http://crbug.com/504661
                   '-Wno-extra-tokens',  # http://crbug.com/504663
                   '-Wno-incompatible-pointer-types',  # http://crbug.com/504696
                   '-Wno-logical-op-parentheses',  # http://crbug.com/504699
                   '-Wno-microsoft',  # http://crbug.com/505296
                   '-Wno-missing-braces',  # http://crbug.com/505297
                   '-Wno-msvc-include',  # http://crbug.com/505299
-                  '-Wno-overloaded-virtual',  # http://crbug.com/505301
                   '-Wno-pointer-sign',  # http://crbug.com/505303
                   '-Wno-reorder',  # http://crbug.com/505304
                   '-Wno-switch',  # http://crbug.com/505308
                   '-Wno-unknown-pragmas',  # http://crbug.com/505314
                   '-Wno-unused-function',  # http://crbug.com/505316
                   '-Wno-unused-private-field',  # http://crbug.com/505317
                   '-Wno-unused-value',  # http://crbug.com/505318
                   '-Wno-unused-variable',  # http://crbug.com/505319
                   '-Wno-unused-local-typedef',  # http://crbug.com/411648
                 ],
@@ skipping 465 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',
   },
 }