Correctly define OVERRIDE when building with g++ 4.7 and C++11 support

g++ 4.7 and later support explicit virtual overrides when building with C++11
support enabled. However, webrtc does not detect that and makes OVERRIDE a
no-op.

This CL updates typedefs.h to define OVERRIDE properly when g++ 4.7 is used
with C++11 support enabled.

See this page for GCC support of C++11 features:
http://gcc.gnu.org/projects/cxx0x.html

R=andrew@webrtc.org, fischman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/5149005

Patch from Chris Dumez <ch.dumez@samsung.com>.

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@5253 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed