enable SK_FONTHOST_USES_FONTMGR for mac and win. linux fontmgr not ready

BUG=

Review URL: https://codereview.chromium.org/22406004

git-svn-id: http://skia.googlecode.com/svn/trunk@10605 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gyp/common_conditions.gypi b/gyp/common_conditions.gypi
index c9d24ae..e046b13 100644
--- a/gyp/common_conditions.gypi
+++ b/gyp/common_conditions.gypi
@@ -32,6 +32,7 @@
       {
         'defines': [
           'SK_BUILD_FOR_WIN32',
+          'SK_FONTHOST_USES_FONTMGR',
           'SK_IGNORE_STDINT_DOT_H',
           '_CRT_SECURE_NO_WARNINGS',
           'GR_GL_FUNCTION_TYPE=__stdcall',
@@ -293,6 +294,7 @@
         },
         'defines': [
           'SK_BUILD_FOR_MAC',
+          'SK_FONTHOST_USES_FONTMGR',
         ],
         'conditions' : [
           [ 'skia_arch_width == 64', {