ios: Simplify -stdlib=libc++ logic.

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 495 matching lines @@
       # Use dynamic libraries instrumented by one of the sanitizers
       # instead of the standard system libraries. Set this flag to download
       # prebuilt binaries from GCS.
       'use_prebuilt_instrumented_libraries%': 0,
 
       # Use libc++ (third_party/libc++ and third_party/libc++abi) instead of
       # stdlibc++ as standard library. This is intended to use for instrumented
       # builds.
       'use_custom_libcxx%': 0,
 
-      # Use system libc++ instead of the default C++ library, usually libstdc++.
-      # This is intended for iOS builds only.
-      'use_system_libcxx%': 0,
-
       # Set to true to instrument the code with function call logger.
       # See src/third_party/cygprofile/cyg-profile.cc for details.
       'order_profiling%': 0,
 
       # Use the provided profiled order file to link Chrome image with it.
       # This makes Chrome faster by better using CPU cache when executing code.
       # This is known as PGO (profile guided optimization).
       # See https://sites.google.com/a/google.com/chrome-msk/dev/boot-speed-up-effort
       'order_text_section%' : "",
 
@@ skipping 337 matching lines @@
           'enable_print_preview%': 0,
           'enable_session_service%': 0,
           'enable_spellcheck%': 0,
           'enable_themes%': 0,
           'enable_webrtc%': 0,
           'notifications%': 0,
           'remoting%': 0,
           'safe_browsing%': 0,
           'enable_supervised_users%': 0,
           'enable_task_manager%': 0,
-          'use_system_libcxx%': 1,
           'enable_media_router%': 0,
         }],
 
         # Use GPU accelerated cross process image transport by default
         # on linux builds with the Aura window manager
         ['use_aura==1 and OS=="linux"', {
           'ui_compositor_image_transport%': 1,
         }, {
           'ui_compositor_image_transport%': 0,
         }],
@@ skipping 303 matching lines @@
     'msan_track_origins%': '<(msan_track_origins)',
     'tsan%': '<(tsan)',
     'tsan_blacklist%': '<(tsan_blacklist)',
     'ubsan%': '<(ubsan)',
     'ubsan_blacklist%': '<(ubsan_blacklist)',
     'ubsan_vptr_blacklist%': '<(ubsan_vptr_blacklist)',
     'ubsan_vptr%': '<(ubsan_vptr)',
     'use_instrumented_libraries%': '<(use_instrumented_libraries)',
     'use_prebuilt_instrumented_libraries%': '<(use_prebuilt_instrumented_libraries)',
     'use_custom_libcxx%': '<(use_custom_libcxx)',
-    'use_system_libcxx%': '<(use_system_libcxx)',
     'order_profiling%': '<(order_profiling)',
     'order_text_section%': '<(order_text_section)',
     'enable_extensions%': '<(enable_extensions)',
     'enable_pdf%': '<(enable_pdf)',
     'enable_plugin_installation%': '<(enable_plugin_installation)',
     'enable_plugins%': '<(enable_plugins)',
     'enable_session_service%': '<(enable_session_service)',
     'enable_themes%': '<(enable_themes)',
     'enable_autofill_dialog%': '<(enable_autofill_dialog)',
     'enable_prod_wallet_service%': '<(enable_prod_wallet_service)',
@@ skipping 4177 matching lines @@
       },  # target_defaults
     }],  # OS=="mac"
     ['OS=="ios"', {
       'includes': [
         'ios/coverage.gypi',
       ],
       'target_defaults': {
         'xcode_settings' : {
           'CLANG_CXX_LANGUAGE_STANDARD': 'c++11',
           'ENABLE_BITCODE': 'NO',
+          'CLANG_CXX_LIBRARY': 'libc++',  # -stdlib=libc++
 
           'conditions': [
             # Older Xcodes do not support -Wno-deprecated-register, so pass an
             # additional flag to suppress the "unknown compiler option" error.
             # Restrict this flag to builds that are either compiling with Xcode
             # or compiling with Xcode's Clang.  This will allow Ninja builds to
             # continue failing on unknown compiler options.
             # TODO(rohitrao): This flag is temporary and should be removed as
             # soon as the iOS bots are updated to use Xcode 5.1.
             ['clang_xcode==1', {
@@ skipping 10 matching lines @@
             # ones (they are used when building for the simulator).
             ['target_subarch=="arm32"', {
               'VALID_ARCHS': ['armv7', 'i386'],
             }],
             ['target_subarch=="arm64"', {
               'VALID_ARCHS': ['arm64', 'x86_64'],
             }],
             ['target_subarch=="both"', {
               'VALID_ARCHS': ['arm64', 'armv7', 'x86_64', 'i386'],
             }],
-            ['use_system_libcxx==1', {
-              'target_conditions': [
-                # Only use libc++ when building target for iOS not when building
-                # tools for the host (OS X) as Mac targets OS X SDK 10.6 which
-                # does not support libc++.
-                ['_toolset=="target"', {
-                  'CLANG_CXX_LIBRARY': 'libc++',  # -stdlib=libc++
-                }]
-              ],
-            }, {
-              # The default for deployment target of 7.0+ is libc++, so force
-              # the old behavior unless libc++ is enabled.
-              'CLANG_CXX_LIBRARY': 'libstdc++',  # -stdlib=libstdc++
-            }],
           ],
         },
         'target_conditions': [
           ['_toolset=="host"', {
             'xcode_settings': {
               'SDKROOT': 'macosx<(mac_sdk)',  # -isysroot
               'MACOSX_DEPLOYMENT_TARGET': '<(mac_deployment_target)',
               'VALID_ARCHS': [
                 'x86_64',
               ],
@@ skipping 847 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',
   },
 }