Allow compositor_unittests to compile on posix

BUG=none
TEST=self


Review URL: http://codereview.chromium.org/8873038

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@113857 0039d316-1c4b-4281-b951-d872f2087c98

ui/gfx/compositor/compositor.gyp

@@ -208,7 +208,7 @@
       'conditions': [
         # We allow on platforms without a compositor (such as OS_WIN).
         # They will use compositor_stub.cc.
-        ['toolkit_views == 1', {
+        ['toolkit_views == 1 or os_posix==1', {
           'dependencies': [
             '<(DEPTH)/skia/skia.gyp:skia',
             'compositor',