Really fix building android webview on mac.

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 5217 matching lines @@
           '-Wno-unused-local-typedefs',
         ],
       },
     }],
     # We need a special case to handle the android webview build on mac because
     # the host gcc there doesn't accept this flag, but the target gcc may
     # require it.
     ['gcc_version>=48 and android_webview_build==1 and host_os=="mac"', {
       'target_defaults': {
         'target_conditions': [
-          ['_toolset=="target"', {
+          ['_toolset=="host"', {
             'cflags!': [
               '-Wno-unused-local-typedefs',
             ],
           }],
         ],
       },
     }],
     ['clang==1 and ((OS!="mac" and OS!="ios") or clang_xcode==0) '
         'and OS!="win"', {
       'make_global_settings': [
@@ skipping 102 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',
   },
 }