Bug 1294660: Part 1 - enable CSS positioned mask on nightly and aurora. r=glandium

MozReview-Commit-ID: HPlYO5EiCOX

old-configure.in

@@ -6103,13 +6103,19 @@ fi
 MOZ_CONFIG_ICU()
 
 dnl ========================================================
-dnl mask as short hand property
+dnl mask as shorthand property
 dnl ========================================================
-dnl Uncommenting the next line would enable mask-as-shorthand feature.
-dnl MOZ_ENABLE_MASK_AS_SHORTHAND=1
-if test "$MOZ_ENABLE_MASK_AS_SHORTHAND"; then
+
+# The control structure code will be removed as soon as the feature is stable
+# Refer to bug 1281101 for more details.
+
+# Enable mask-as-shorthand property by default for nightly and aurora channels
+if test -z "$RELEASE_BUILD"; then
+  dnl mask as shorthand property enabled
+  MOZ_ENABLE_MASK_AS_SHORTHAND=1
   AC_DEFINE(MOZ_ENABLE_MASK_AS_SHORTHAND)
 fi
+
 AC_SUBST(MOZ_ENABLE_MASK_AS_SHORTHAND)
 
 # Avoid using obsolete NSPR features