android_webview: explicitly use gcc for target binaries.

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 5567 matching lines @@
     ['gcc_version>=48 and clang==0 and host_clang==1', {
       'target_defaults': {
         'target_conditions': [
           ['_toolset=="host"', { 'cflags!': [ '-Wno-unused-local-typedefs' ]}],
         ],
       },
     }],
     # In the android webview build, force host targets to be compiled with clang
     # as the hermetic host gcc is very old on some platforms. This is already
     # the default on the current development version of AOSP but we force it
-    # here in case we need to compile against an older release version.
+    # here in case we need to compile against an older release version. We also
+    # explicitly set it to false for target binaries to avoid causing problems
+    # for the work to enable clang by default in AOSP.
     ['android_webview_build==1', {
       'target_defaults': {
         'target_conditions': [
           ['_toolset=="host"', {
             'aosp_build_settings': {
               'LOCAL_CLANG': 'true',
             },
+          }, {  # else: _toolset != "host"
+            'aosp_build_settings': {
+              'LOCAL_CLANG': 'false',
+            },
           }],
         ],
       },
     }],
     # 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': [
@@ skipping 123 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',
   },
 }