Use devtools to set user agent in chromedriver

chrome/test/chromedriver/chrome/web_view_impl.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_WEB_VIEW_IMPL_H_
 #define CHROME_TEST_CHROMEDRIVER_CHROME_WEB_VIEW_IMPL_H_
 
 #include <list>
 #include <memory>
 #include <string>
@@ skipping 23 matching lines @@
 class PageLoadStrategy;
 class Status;
 
 class WebViewImpl : public WebView {
  public:
   WebViewImpl(const std::string& id,
               const bool w3c_compliant,
               const BrowserInfo* browser_info,
               std::unique_ptr<DevToolsClient> client,
               const DeviceMetrics* device_metrics,
-              std::string page_load_strategy);
+              std::string page_load_strategy,
+              std::string user_agent);
   ~WebViewImpl() override;
 
   // Overridden from WebView:
   std::string GetId() override;
   bool WasCrashed() override;
   Status ConnectIfNecessary() override;
   Status HandleReceivedEvents() override;
   Status GetUrl(std::string* url) override;
   Status Load(const std::string& url, const Timeout* timeout) override;
   Status Reload(const Timeout* timeout) override;
@@ skipping 115 matching lines @@
                              int context_id,
                              const std::string& function,
                              const base::ListValue& args,
                              bool* found_node,
                              int* node_id,
                              bool w3c_compliant);
 
 }  // namespace internal
 
 #endif  // CHROME_TEST_CHROMEDRIVER_CHROME_WEB_VIEW_IMPL_H_