Fix iOS build for XCode 4.6.

chrome/common/mac/objc_zombie.mm

Index: chrome/common/mac/objc_zombie.mm
diff --git a/chrome/common/mac/objc_zombie.mm b/chrome/common/mac/objc_zombie.mm
index 0f01a529d031a914f32a40902f1296e3c45b3401..b3bb2e34e623b3364ac1e5b7eda623cbf67a42b1 100644
--- a/chrome/common/mac/objc_zombie.mm
+++ b/chrome/common/mac/objc_zombie.mm
@@ -34,7 +34,11 @@ OBJC_EXPORT void *objc_destructInstance(id obj);
 //  The version of clang that ships with Xcode 4.5 does not include this
 //  warning, so it is disabled on iOS.  This may change in future Xcode
 //  releases.
-#if !defined(OS_IOS)
+// TODO(justincohen): This is fixed in clang 4.2 in XCode 4.6.  Remove this once
+// everyone is moved to XCode 4.6 b/7882496.

[wtc, 2013/01/04 00:58:36]

Nit: the indentation of this TODO comment should match lines
34-36 to make it clearer that the TODO is referring to lines
34-36 rather than lines 28-32.

[justincohen, 2013/01/04 03:54:10]

Done.

+#if !defined(OS_IOS) || \
+    (defined(OS_IOS) && \

[wtc, 2013/01/04 00:58:36]

Nit: defined(OS_IOS) is not necessary. If you prefer having it,
that's fine by me.

[justincohen, 2013/01/04 03:54:10]

Done.

+     (__clang_major__ > 4 || (__clang_major__ == 4 && __clang_minor__ >= 2)))
 __attribute__((objc_root_class))
 #endif
 @interface CrZombie  {