headless: Make it possible to configure an HTTP proxy

headless/lib/browser/headless_browser_context.cc

 // 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.
 
 #include "headless/lib/browser/headless_browser_context.h"
 
 #include "base/path_service.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/resource_context.h"
 #include "content/public/browser/storage_partition.h"
@@ skipping 138 matching lines @@
 
 content::PermissionManager* HeadlessBrowserContext::GetPermissionManager() {
   return nullptr;
 }
 
 content::BackgroundSyncController*
 HeadlessBrowserContext::GetBackgroundSyncController() {
   return nullptr;
 }
 
+void HeadlessBrowserContext::SetOptionsForTesting(
+    const HeadlessBrowser::Options& options) {
+  options_ = options;
+}
+
 void HeadlessBrowserContext::SetURLRequestContextGetter(
     scoped_refptr<net::URLRequestContextGetter> url_request_context_getter) {
   resource_context_->set_url_request_context_getter(url_request_context_getter);
 }
 
 }  // namespace headless