Put back -fno-rtti which I somehow accidentally checked in.

TEST=none
BUG=none
Review URL: http://codereview.chromium.org/342021

git-svn-id: http://src.chromium.org/svn/trunk/src/build@30371 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

common.gypi

@@ -498,7 +498,7 @@
           '-D_FILE_OFFSET_BITS=64',
         ],
         'cflags_cc': [
-          #'-fno-rtti',
+          '-fno-rtti',
           '-fno-threadsafe-statics',
         ],
         'ldflags': [