Use the /WX flag to have link warnings treated as errors.

media/mojo/services/BUILD.gn

 # Copyright 2014 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("//media/media_options.gni")
 import("//services/service_manager/public/cpp/service.gni")
 import("//services/service_manager/public/service_manifest.gni")
 import("//testing/test.gni")
 
 config("mojo_media_config") {
@@ skipping 114 matching lines @@
     sources += [
       "android_mojo_media_client.cc",
       "android_mojo_media_client.h",
     ]
   }
 }
 
 service("media") {
   testonly = true
 
+  # crbug.com/676418: Suppress symbol import warnings.
+  if (is_win && is_component_build) {
+    ldflags = [ "/ignore:4217" ]
+  }
+
   sources = [
     "main.cc",
   ]
 
   public_deps = [
     "//base",
     "//media",
   ]
 
   deps = [
@@ skipping 58 matching lines @@
   data_deps = [
     ":media",
     ":pipeline_test_manifest",
   ]
 }
 
 service_manifest("pipeline_test_manifest") {
   name = "media_pipeline_integration_unittests"
   source = "pipeline_test_manifest.json"
 }