Revert the addition of -fno-threadsafe-statics. It breaks the build:

build/common.gypi

 # Copyright (c) 2009 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.
 
 {
   'variables': {
     # .gyp files should set chromium_code to 1 if they build Chromium-specific
     # code, as opposed to external code.  This variable is used to control
     # such things as the set of warnings to enable, and whether warnings are
     # treated as errors.
@@ skipping 332 matching lines @@
                 'cflags': [
                   '-march=pentium4',
                   '-msse2',
                   '-mfpmath=sse',
                 ],
               }],
             ],
             'cflags': [
               '-m32',
               '-fno-exceptions',
-              '-fno-threadsafe-statics',
               '-Wall',
             ],
             'ldflags': [
               '-m32',
             ],
           }],
         ],
       },
     }],
     ['OS=="mac"', {
@@ skipping 176 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',
   },
 }