drawfilter is legacy-guarded, no need for deprecated

Bug: skia:
Change-Id: Ic8dbe9aa043bd793e49975f5b6f08a0ac38e4faa
Reviewed-on: https://skia-review.googlesource.com/15185
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index 76cfbd2..539767a 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -139,10 +139,7 @@
     "third_party/gif",
   ]
 
-  defines = [
-    "SK_GAMMA_APPLY_TO_A8",
-    "SK_INTERNAL",
-  ]
+  defines = [ "SK_GAMMA_APPLY_TO_A8" ]
   if (is_android) {
     defines += [
       "SK_GAMMA_EXPONENT=1.4",