add print to pdf for headless

headless/lib/headless_content_main_delegate.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_HEADLESS_CONTENT_MAIN_DELEGATE_H_
 #define HEADLESS_LIB_HEADLESS_CONTENT_MAIN_DELEGATE_H_
 
 #include <memory>
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "content/public/app/content_main_delegate.h"
 #include "headless/lib/browser/headless_platform_event_source.h"
 #include "headless/lib/headless_content_client.h"
 #include "headless/public/headless_export.h"
 
 namespace base {
 class CommandLine;
 }
 
 namespace headless {
 
 class HeadlessBrowserImpl;
 class HeadlessContentBrowserClient;
+class HeadlessContentRendererClient;
 
 // Exported for tests.
 class HEADLESS_EXPORT HeadlessContentMainDelegate
     : public content::ContentMainDelegate {
  public:
   explicit HeadlessContentMainDelegate(
       std::unique_ptr<HeadlessBrowserImpl> browser);
   ~HeadlessContentMainDelegate() override;
 
   // content::ContentMainDelegate implementation:
   bool BasicStartupComplete(int* exit_code) override;
   void PreSandboxStartup() override;
   int RunProcess(
       const std::string& process_type,
       const content::MainFunctionParams& main_function_params) override;
   content::ContentBrowserClient* CreateContentBrowserClient() override;
+  content::ContentRendererClient* CreateContentRendererClient() override;
 
   HeadlessBrowserImpl* browser() const { return browser_.get(); }
 
 #if !defined(OS_MACOSX) && defined(OS_POSIX) && !defined(OS_ANDROID)
   void ZygoteForked() override;
 #endif
 
  private:
   friend class HeadlessBrowserTest;
 
   void InitLogging(const base::CommandLine& command_line);
   void InitCrashReporter(const base::CommandLine& command_line);
   static void InitializeResourceBundle();
 
   static HeadlessContentMainDelegate* GetInstance();
 
   std::unique_ptr<HeadlessContentBrowserClient> browser_client_;
+  std::unique_ptr<HeadlessContentRendererClient> renderer_client_;
   HeadlessContentClient content_client_;
   HeadlessPlatformEventSource platform_event_source_;
 
   std::unique_ptr<HeadlessBrowserImpl> browser_;
 
   DISALLOW_COPY_AND_ASSIGN(HeadlessContentMainDelegate);
 };
 
 }  // namespace headless
 
 #endif  // HEADLESS_LIB_HEADLESS_CONTENT_MAIN_DELEGATE_H_