remove poplar building from mac, until it is fixed

BUG=skia:2008
R=mtklein@google.com, vandebo@chromium.org

Author: reed@google.com

Review URL: https://codereview.chromium.org/134243002

git-svn-id: http://skia.googlecode.com/svn/trunk@13020 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gyp/common_variables.gypi b/gyp/common_variables.gypi
index 1c6111a..64753a3 100644
--- a/gyp/common_variables.gypi
+++ b/gyp/common_variables.gypi
@@ -57,7 +57,7 @@
         }, {
           'os_posix%': 1,
         }],
-        [ 'skia_os in ["linux", "win", "mac"]', {
+        [ 'skia_os in ["linux", "win"]', {
           'skia_poppler_enabled%': 1,
         }, {
           'skia_poppler_enabled%': 0,