Add an option to disable NaCl at compile time for platforms where it doesn't build yet

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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   'variables': {
     # .gyp files should set chromium_code to 1 if they build Chromium-specific
@@ skipping 136 matching lines @@
 
     # Set this to true to enable SELinux support.
     'selinux%': 0,
 
     # Strip the binary after dumping symbols.
     'linux_strip_binary%': 0,
 
     # Set to select the Title Case versions of strings in GRD files.
     'use_titlecase_in_grd_files%': 0,
 
+    # Used to disable Native Client at compile time, for platforms where it
+    # isn't supported
+    'disable_nacl%': 0,
+
     'conditions': [
       ['OS=="linux"', {
         'conditions': [
           ['branding=="Chrome" or linux_chromium_breakpad==1', {
             'linux_breakpad%': 1,
           }, {
             'linux_breakpad%': 0,
           }],
           # All Chrome builds have breakpad symbols, but only process the
           # symbols from official builds.
@@ skipping 673 matching lines @@
       ],
     }, {
       'target_defaults': {
         # In Chromium code, we define __STDC_FORMAT_MACROS in order to get the
         # C99 macros on Mac and Linux.
         'defines': [
           '__STDC_FORMAT_MACROS',
         ],
       },
     }],
+    ['disable_nacl==1', {
+      'target_defaults': {
+        'defines': [
+          'DISABLE_NACL',
+        ],
+      },
+    }],
     ['msvs_use_common_linker_extras', {
       'target_defaults': {
         'msvs_settings': {
           'VCLinkerTool': {
             'AdditionalOptions':
               '/safeseh /dynamicbase /ignore:4199 /ignore:4221 /nxcompat',
             'DelayLoadDLLs': [
               'dbghelp.dll',
               'dwmapi.dll',
               'uxtheme.dll',
@@ skipping 15 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',
   },
 }