Use devtools to set user agent in chromedriver

chrome/test/chromedriver/chrome/devtools_http_client.h

 // Copyright (c) 2013 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.
 
 #ifndef CHROME_TEST_CHROMEDRIVER_CHROME_DEVTOOLS_HTTP_CLIENT_H_
 #define CHROME_TEST_CHROMEDRIVER_CHROME_DEVTOOLS_HTTP_CLIENT_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 61 matching lines @@
   std::vector<WebViewInfo> views_info;
 };
 
 class DevToolsHttpClient {
  public:
   DevToolsHttpClient(const NetAddress& address,
                      scoped_refptr<URLRequestContextGetter> context_getter,
                      const SyncWebSocketFactory& socket_factory,
                      std::unique_ptr<DeviceMetrics> device_metrics,
                      std::unique_ptr<std::set<WebViewInfo::Type>> window_types,
-                     std::string page_load_strategy);
+                     std::string page_load_strategy,
+                     std::string user_agent);
   ~DevToolsHttpClient();
 
   Status Init(const base::TimeDelta& timeout);
 
   Status GetWebViewsInfo(WebViewsInfo* views_info);
 
   std::unique_ptr<DevToolsClient> CreateClient(const std::string& id);
 
   Status CloseWebView(const std::string& id);
 
   Status ActivateWebView(const std::string& id);
 
   const BrowserInfo* browser_info();
   const DeviceMetrics* device_metrics();
   bool IsBrowserWindow(const WebViewInfo& view) const;
+  const std::string& user_agent() const;
 
  private:
   Status CloseFrontends(const std::string& for_client_id);
   bool FetchUrlAndLog(const std::string& url,
                       URLRequestContextGetter* getter,
                       std::string* response);
 
   scoped_refptr<URLRequestContextGetter> context_getter_;
   SyncWebSocketFactory socket_factory_;
   std::string server_url_;
   std::string web_socket_url_prefix_;
   BrowserInfo browser_info_;
   std::unique_ptr<DeviceMetrics> device_metrics_;
   std::unique_ptr<std::set<WebViewInfo::Type>> window_types_;
   std::string page_load_strategy_;
+  std::string user_agent_;
 
   DISALLOW_COPY_AND_ASSIGN(DevToolsHttpClient);
 };
 
 Status ParseType(const std::string& data, WebViewInfo::Type* type);
 
 namespace internal {
 Status ParseWebViewsInfo(const std::string& data, WebViewsInfo* views_info);
 }  // namespace internal
 
 #endif  // CHROME_TEST_CHROMEDRIVER_CHROME_DEVTOOLS_HTTP_CLIENT_H_