Fix building android webview on arm64 on mac.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index def3eaf76e23551abde55b878fbd2ab7ab6703de..2232e424bc8cfc228abc745940fbe96c743582fd 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -5127,15 +5127,28 @@
       },
     }],
     # Don't warn about the "typedef 'foo' locally defined but not used"
-    # for gcc 4.8.
+    # for gcc 4.8. 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.
     # TODO: remove this flag once all builds work. See crbug.com/227506
-    ['gcc_version>=48', {
+    ['gcc_version>=48 and (android_webview_build==0 or host_os!="mac")', {

[Nico, 2014/05/09 15:30:39]

I'd revert this part…

       'target_defaults': {
         'cflags': [
           '-Wno-unused-local-typedefs',
         ],
       },
     }],
+    ['gcc_version>=48 and android_webview_build==1 and host_os=="mac"', {

[Nico, 2014/05/09 15:30:39]

and instead do cflags! here and remove it again.

+      'target_defaults': {
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'cflags': [
+              '-Wno-unused-local-typedefs',
+            ],
+          }],
+        ],
+      },
+    }],
     ['clang==1 and ((OS!="mac" and OS!="ios") or clang_xcode==0) '
         'and OS!="win"', {
       'make_global_settings': [