Merge pull request #617 from edx/db/add-theme-feature-var

USE_CUSTOM_THEME

playbooks/roles/edxapp/defaults/main.yml

@@ -66,6 +66,7 @@ EDXAPP_FEATURES:
   SUBDOMAIN_COURSE_LISTINGS: false
   PREVIEW_LMS_BASE: $EDXAPP_PREVIEW_LMS_BASE
   ENABLE_S3_GRADE_DOWNLOADS: true
+  USE_CUSTOM_THEME: $edxapp_use_custom_theme
 
 EDXAPP_BOOK_URL: ''
 # This needs to be set to localhost
@@ -429,9 +430,12 @@ worker_core_mult:
   cms: 2
 
 # Theming
-# To turn off theming, specify edxapp_theme_name: ""
+# Turn theming on and off with edxapp_use_custom_theme
+# Set theme name with edxapp_theme_name
 # Stanford, for example, uses edxapp_theme_name: 'stanford'
 #
+# TODO: change variables to ALL-CAPS, since they are meant to be externally overridden
+edxapp_use_custom_theme: false
 edxapp_theme_name: ""
 edxapp_theme_source_repo: 'https://{{ COMMON_GIT_MIRROR }}/Stanford-Online/edx-theme.git'
 edxapp_theme_version: 'HEAD'