Enable new clip stack for Fuchsia

Bug: skia:10205
Change-Id: I9d9ead1d40c34cd31ce0235e773de20f36f93e32
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/325816
Auto-Submit: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>

Author: lhkbob

gn/fuchsia_defines.gni

@@ -3,7 +3,4 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-fuchsia_defines = [
-  # Staging
-  "SK_DISABLE_NEW_GR_CLIP_STACK",
-]
+fuchsia_defines = []