Adds -Wno-deprecated-register to the build settings for iOS.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 28e3389b76fe724be78b51b54f52bc61a5c1b274..c353199e220cd9866e74385aa45d9ca60aa14c31 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -4463,12 +4463,27 @@
             '-Wno-unneeded-internal-declaration',
             # Match OS X clang C++11 warning settings.
             '-Wno-c++11-narrowing',
+            # As of Xcode 5.1, the register keyword is deprecated, but Chromium
+            # code still uses it.
+            '-Wno-deprecated-register',

[rohitrao (ping after 24h), 2014/03/11 21:09:39]

-Wno-deprecated-register is now passed *twice* for iOS ninja builds.  It's added
once in the "mac or ios, clang==1" section above, and a second time here.

Is this a big deal?  The alternative is to conditionally add it in the iOS block
if ("<(GENERATOR)"=="xcode").

(Do we still support building Mac with Xcode?  Could we just unconditionally add
-Wno-deprecated-register and break Xcode builds, or would that make people mad?

[Mark Mentovai, 2014/03/11 21:39:52]

rohitrao wrote:
I’m taking that to mean that you’re not always using clang? Really?

[rohitrao (ping after 24h), 2014/03/11 21:49:31]

"clang==1" is only true if you're using Ninja.  It's false for Xcode builds. 
Most developers are on ninja by now, but the bots (and official builders) are
still using Xcode.

Xcode itself is using clang too, but that doesn't mean "clang==1" =)

[Mark Mentovai, 2014/03/11 21:55:46]

rohitrao wrote:
That sounds wrongish to me.

If you’re using clang everywhere, can you set clang=1 even in your Xcode builds?

           ],
 
           # Limit the valid architectures depending on "target_subarch".

[Mark Mentovai, 2014/03/11 21:39:52]

This comment goes with the target_subarch conditions that were already there,
but now you’ve separated them.

[rohitrao (ping after 24h), 2014/03/11 21:49:31]

Done.

           # This need to include the "arm" architectures but also the "x86"
           # ones (they are used when building for the simulator).
           '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.
+            ['"<(GENERATOR)"=="xcode" or clang_xcode==1', {
+              'WARNING_CFLAGS': [
+                '-Wno-unknown-warning-option',
+              ],
+            }],
             ['target_subarch=="arm32"', {
               'VALID_ARCHS': ['armv7', 'i386'],
             }],