GTTF: Fix build with _GLIBCXX_DEBUG

BUG=65151
TEST=none


Review URL: https://chromiumcodereview.appspot.com/11238074

git-svn-id: http://src.chromium.org/svn/trunk/src/build@163882 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

common.gypi

@@ -1568,8 +1568,7 @@
       }],
       ['OS=="linux" and glibcxx_debug==1', {
         'defines': ['_GLIBCXX_DEBUG=1',],
-        'cflags_cc!': ['-fno-rtti'],
-        'cflags_cc+': ['-frtti', '-g'],
+        'cflags_cc+': ['-g'],
       }],
       ['remoting==1', {
         'defines': ['ENABLE_REMOTING=1'],