do not hardcode -I/usr/include32 when cross-compiling

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 3843 matching lines @@
                     'ldflags': [
                       '-fuse-ld=gold',
                     ],
                   }],
                   # Install packages have started cropping up with
                   # different headers between the 32-bit and 64-bit
                   # versions, so we have to shadow those differences off
                   # and make sure a 32-bit-on-64-bit build picks up the
                   # right files.
                   # For android build, use NDK headers instead of host headers
-                  ['host_arch!="ia32" and OS!="android"', {
+                  ['host_arch!="ia32" and OS!="android" and use_sysroot!=1', {
                     'include_dirs+': [
                       '/usr/include32',
                     ],
                   }],
                 ],
               }],
             ],
           }],
           ['target_arch=="x64"', {
             'target_conditions': [
@@ skipping 2314 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',
   },
 }