Remove unnecessary dependencies on mojo/edk/system

mojo/converters/blink/BUILD.gn

 # 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.
 
 import("//testing/test.gni")
 
 component("blink") {
   output_name = "mojo_blink_lib"
 
   sources = [
@@ skipping 18 matching lines @@
 
 test("blink_converters_unittests") {
   sources = [
     "blink_input_events_type_converters_unittest.cc",
   ]
   deps = [
     ":blink",
     "//base:message_loop_tests",
     "//base/test:run_all_unittests",
     "//base/test:test_support",
-    "//mojo/edk/test:test_support",
     "//mojo/public/cpp/bindings:bindings",
     "//testing/gtest",
     "//third_party/WebKit/public:blink",
     "//ui/events",
   ]
 }