[headless] Remove default browser context.

headless/lib/browser/headless_browser_main_parts.h

 // 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.
 
 #ifndef HEADLESS_LIB_BROWSER_HEADLESS_BROWSER_MAIN_PARTS_H_
 #define HEADLESS_LIB_BROWSER_HEADLESS_BROWSER_MAIN_PARTS_H_
 
 #include <memory>
 
 #include "content/public/browser/browser_main_parts.h"
@@ skipping 10 matching lines @@
 
 class HeadlessBrowserMainParts : public content::BrowserMainParts {
  public:
   explicit HeadlessBrowserMainParts(HeadlessBrowserImpl* browser);
   ~HeadlessBrowserMainParts() override;
 
   // content::BrowserMainParts implementation:
   void PreMainMessageLoopRun() override;
   void PostMainMessageLoopRun() override;
 
-  HeadlessBrowserContextImpl* default_browser_context() const;
-
  private:
   HeadlessBrowserImpl* browser_;  // Not owned.
-  std::unique_ptr<HeadlessBrowserContextImpl> browser_context_;
   std::unique_ptr<devtools_http_handler::DevToolsHttpHandler>
       devtools_http_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(HeadlessBrowserMainParts);
 };
 
 }  // namespace headless
 
 #endif  // HEADLESS_LIB_BROWSER_HEADLESS_BROWSER_MAIN_PARTS_H_