Update fuzzer_test.gni: add seed_corpuses attribute into noop branch.

testing/libfuzzer/fuzzer_test.gni

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Defines fuzzer_test.
 #
 import("//build/config/features.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//testing/test.gni")
 
@@ skipping 137 matching lines @@
     }
     if (defined(invoker.dict)) {
       assert(invoker.dict == [] || invoker.dict != [])
     }
     if (defined(invoker.libfuzzer_options)) {
       assert(invoker.libfuzzer_options == [] || invoker.libfuzzer_options != [])
     }
     if (defined(invoker.seed_corpus)) {
       assert(invoker.seed_corpus == [] || invoker.seed_corpus != [])
     }
+    if (defined(invoker.seed_corpuses)) {
+      assert(invoker.seed_corpuses == [] || invoker.seed_corpuses != [])
+    }
     assert(!defined(invoker.check_includes) || invoker.check_includes != [])
     assert(!defined(invoker.include_dirs) || invoker.include_dirs != [])
     assert(!defined(invoker.defines) || invoker.defines != [])
 
     group(target_name) {
     }
   }
 }