Bug 1257104 - Move MOZ_APPLEMEDIA to moz.configure. r=ted

Note the AC_DEFINE used to be in a COMPILE_ENVIRONMENT block, but the
define is actually used in Gecko preferences, so it's actually better
that the define is always set when MOZ_APPLEMEDIA is enabled.

old-configure.in

@@ -4325,13 +4325,8 @@ fi
 dnl ========================================================
 dnl = Apple platform decoder support
 dnl ========================================================
-if test "$MOZ_WIDGET_TOOLKIT" = "cocoa" || test "$MOZ_WIDGET_TOOLKIT" = "uikit"; then
-  MOZ_APPLEMEDIA=1
-fi
-
 if test "$COMPILE_ENVIRONMENT"; then
 if test -n "$MOZ_APPLEMEDIA"; then
-  AC_DEFINE(MOZ_APPLEMEDIA)
   # hack in frameworks for fmp4 - see bug 1029974
   # We load VideoToolbox and CoreMedia dynamically, so they don't appear here.
   LDFLAGS="$LDFLAGS -framework AudioToolbox"
@@ -8024,7 +8019,6 @@ AC_SUBST(MOZ_FMP4)
 AC_SUBST(MOZ_EME)
 AC_SUBST(MOZ_DIRECTSHOW)
 AC_SUBST(MOZ_ANDROID_OMX)
-AC_SUBST(MOZ_APPLEMEDIA)
 AC_SUBST(MOZ_OMX_PLUGIN)
 AC_SUBST(MOZ_BUILD_MOBILE_ANDROID_WITH_GRADLE)
 AC_SUBST(MOZ_VPX_ERROR_CONCEALMENT)

toolkit/moz.configure

@@ -145,3 +145,15 @@ def fc_freetype(value, toolkit):
     if value or (toolkit in ('gtk2', 'gtk3', 'qt') and
                  value.origin == 'default'):
         add_old_configure_assignment('USE_FC_FREETYPE', '1')
+
+
+# Apple platform decoder support
+# ==============================================================
+@depends(toolkit)
+def applemedia(toolkit):
+    if toolkit in ('cocoa', 'uikit'):
+        set_config('MOZ_APPLEMEDIA', '1')
+        set_define('MOZ_APPLEMEDIA', '1')
+        add_old_configure_assignment('MOZ_APPLEMEDIA', '1')
+        return True
+    return False