DevTools: allow embedder handling async remote debugger commands.

content/browser/devtools/protocol/page_handler.h

 // Copyright 2014 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 CONTENT_BROWSER_DEVTOOLS_PROTOCOL_PAGE_HANDLER_H_
 #define CONTENT_BROWSER_DEVTOOLS_PROTOCOL_PAGE_HANDLER_H_
 
 #include <stddef.h>
 
 #include "base/compiler_specific.h"
@@ skipping 54 matching lines @@
   using NavigationEntries = protocol::Array<Page::NavigationEntry>;
   Response GetNavigationHistory(
       int* current_index,
       std::unique_ptr<NavigationEntries>* entries) override;
   Response NavigateToHistoryEntry(int entry_id) override;
 
   void CaptureScreenshot(
       Maybe<std::string> format,
       Maybe<int> quality,
       std::unique_ptr<CaptureScreenshotCallback> callback) override;
+  void PrintToPDF(std::unique_ptr<PrintToPDFCallback> callback) override;
   Response StartScreencast(Maybe<std::string> format,
                            Maybe<int> quality,
                            Maybe<int> max_width,
                            Maybe<int> max_height,
                            Maybe<int> every_nth_frame) override;
   Response StopScreencast() override;
   Response ScreencastFrameAck(int session_id) override;
 
   Response HandleJavaScriptDialog(bool accept,
                                   Maybe<std::string> prompt_text) override;
@@ skipping 63 matching lines @@
   NotificationRegistrar registrar_;
   base::WeakPtrFactory<PageHandler> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PageHandler);
 };
 
 }  // namespace protocol
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DEVTOOLS_PROTOCOL_PAGE_HANDLER_H_