Feed Clang a pragma to ignore -Wc++11-extensions to let it build Skia on Mac.

Feed Clang a pragma to ignore -Wc++11-extensions to let it build Skia on Mac.

Tested:
CXX=clang++ ./gyp_skia && ninja -C out/Debug && CXX=G++ ./gyp_skia && ninja -C out/Debug && echo "ok"

Got to ok.

BUG=

Committed: http://code.google.com/p/skia/source/detail?r=8799

[mtklein, 2013-04-19 03:23:02]

Clang turned out to be easy!

[mtklein, 2013-04-19 03:49:16]

Had to change the approach a little.  Apple's GCC doesn't know
-Wno-c++11-extensions.

[bungeman-skia, 2013-04-19 15:20:58]

I don't like it, but I can't find a more acceptable means of doing this. lgtm.

[commit-bot: I haz the power, 2013-04-19 15:44:34]

CQ is trying da patch. Follow status at
https://skia-tree-status.appspot.com/cq/mtklein@google.com/14365009/3001

[rmistry, 2013-04-22 12:34:10]

On 2013/04/19 15:44:34, I haz the power (commit-bot) wrote:
> CQ is trying da patch. Follow status at
> https://skia-tree-status.appspot.com/cq/mtklein%40google.com/14365009/3001

CQ was stuck because some bots were offline due to a tripped breaker. They
should be coming up shortly now.

[commit-bot: I haz the power, 2013-04-22 14:39:07]

Change committed as 8799

[mtklein, 2013-04-22 14:41:11]

On 2013/04/22 12:34:10, rmistry wrote:
> On 2013/04/19 15:44:34, I haz the power (commit-bot) wrote:
> > CQ is trying da patch. Follow status at
> > https://skia-tree-status.appspot.com/cq/mtklein%2540google.com/14365009/3001
> 
> CQ was stuck because some bots were offline due to a tripped breaker. They
> should be coming up shortly now.

Ah, was wondering.  Thanks!