Add Network.setSendRequestIdHeader and use it in headless

headless/test/headless_browser_test.h

 // Copyright 2016 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 HEADLESS_TEST_HEADLESS_BROWSER_TEST_H_
 #define HEADLESS_TEST_HEADLESS_BROWSER_TEST_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 99 matching lines @@
   // HeadlessWebContentsObserver implementation:
   void DevToolsTargetReady() override;
   void RenderProcessExited(base::TerminationStatus status,
                            int exit_code) override;
 
   // Implemented by tests and used to send request(s) to DevTools. Subclasses
   // need to ensure that FinishAsynchronousTest() is called after response(s)
   // are processed (e.g. in a callback).
   virtual void RunDevTooledTest() = 0;
 
+  // Returns the protocol handlers to construct the browser with.  By default
+  // the map returned is empty.
+  virtual ProtocolHandlerMap GetProtocolHandlers();
+
  protected:
   void RunTest();
 
   HeadlessBrowserContext* browser_context_;  // Not owned.
   HeadlessWebContents* web_contents_;
   std::unique_ptr<HeadlessDevToolsClient> devtools_client_;
   bool render_process_exited_;
 };
 
 }  // namespace headless
 
 #endif  // HEADLESS_TEST_HEADLESS_BROWSER_TEST_H_