Revert 259371 "clang roll 198389:202554 reloaded"

trunk/src/third_party/libxml/libxml.gyp

 # 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.
 
 {
   'variables': {
     'conditions': [
       # Define an "os_include" variable that points at the OS-specific generated
       # headers.  These were generated by running the configure script offline.
       ['os_posix == 1 and OS != "mac" and OS != "ios"', {
@@ skipping 225 matching lines @@
             ['clang==1', {
               'xcode_settings': {
                 'WARNING_CFLAGS': [
                   # libxml passes `const unsigned char*` through `const char*`.
                   '-Wno-pointer-sign',
                   # pattern.c and uri.c both have an intentional
                   # `for (...);` / `while(...);` loop. I submitted a patch to
                   # move the `'` to its own line, but until that's landed
                   # suppress the warning:
                   '-Wno-empty-body',
-                  # debugXML.c compares array 'arg' to NULL.
-                  '-Wno-tautological-pointer-compare',
                 ],
               },
               'cflags': [
                 '-Wno-pointer-sign',
                 '-Wno-empty-body',
-                '-Wno-tautological-pointer-compare',
 
                 # See http://crbug.com/138571#c8
                 '-Wno-ignored-attributes',
               ],
               'msvs_settings': {
                 'VCCLCompilerTool': {
                   'AdditionalOptions': [
                     # VS2012's standard lib doesn't provide nan().
                     '/U__STDC_VERSION__',
                   ],
                 },
               },
             }],
           ],
         }],
       ],
     },
   ],
 }