Add gclient_gn_args_from var to DEPS

This fixes RecreateSKPs.

Bug: skia:6951
Change-Id: Ifde19a0d281410aef3094e09fb8c2a9f3f23a979
Reviewed-on: https://skia-review.googlesource.com/136168
Reviewed-by: Ravi Mistry <rmistry@google.com>
Commit-Queue: Eric Boren <borenet@google.com>
diff --git a/DEPS b/DEPS
index 2fbe336..2bcb1b1 100644
--- a/DEPS
+++ b/DEPS
@@ -45,3 +45,5 @@
   "common",
   "../src",
 ]
+
+gclient_gn_args_from = 'src'