More chrome_browser.gypi cleanup once chromeos_gtk is gone.

BUG=none
TEST=none

Review URL: https://chromiumcodereview.appspot.com/9717014

git-svn-id: http://src.chromium.org/svn/trunk/src/build@127481 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

common.gypi

@@ -59,7 +59,7 @@
               '<!(uname -m | sed -e "s/i.86/ia32/;s/x86_64/x64/;s/amd64/x64/;s/arm.*/arm/;s/i86pc/ia32/")',
           }],
 
-          # Non-GTK Chromeos implies ash.
+          # Chromeos implies ash.
           ['chromeos==1', {
             'use_ash%': 1,
             'use_aura%': 1,