Refactor MHTMLGenerator to allow getting sending the data to a file descriptor.

content/browser/download/mhtml_generation_manager.h

 // Copyright (c) 2012 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_DOWNLOAD_MHTML_GENERATION_MANAGER_H_
 #define CONTENT_BROWSER_DOWNLOAD_MHTML_GENERATION_MANAGER_H_
 
 #include <map>
 
 #include "base/memory/singleton.h"
 #include "base/platform_file.h"
 #include "base/process/process.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "ipc/ipc_platform_file.h"
 
 namespace base {
 class FilePath;
 }
 
 namespace content {
 class WebContents;
 
 class MHTMLGenerationManager : public NotificationObserver {
  public:
   static MHTMLGenerationManager* GetInstance();
 
-  typedef base::Callback<void(const base::FilePath& /* path to the MHTML file */,
-      int64 /* size of the file */)> GenerateMHTMLCallback;
+  typedef base::Callback<void(int64 /* size of the file */)>
+      GenerateMHTMLCallback;
 
   // Instructs the render view to generate a MHTML representation of the current
   // page for |web_contents|.
-  void GenerateMHTML(WebContents* web_contents,
-                     const base::FilePath& file,
-                     const GenerateMHTMLCallback& callback);
+  void SaveMHTML(WebContents* web_contents,
+                 const base::FilePath& file,
+                 const GenerateMHTMLCallback& callback);
+
+  // Instructs the render view to generate a MHTML representation of the current
+  // page for |web_contents|.
+  void StreamMHTML(WebContents* web_contents,
+                   const base::PlatformFile file,
+                   const GenerateMHTMLCallback& callback);
 
   // Notification from the renderer that the MHTML generation finished.
   // |mhtml_data_size| contains the size in bytes of the generated MHTML data,
   // or -1 in case of failure.
   void MHTMLGenerated(int job_id, int64 mhtml_data_size);
 
  private:
   friend struct DefaultSingletonTraits<MHTMLGenerationManager>;
 
   struct Job{
     Job();
     ~Job();
 
-    base::FilePath file_path;
-
     // The handles to file the MHTML is saved to, for the browser and renderer
     // processes.
     base::PlatformFile browser_file;
     IPC::PlatformFileForTransit renderer_file;
 
     // The IDs mapping to a specific contents.
     int process_id;
     int routing_id;
 
     // The callback to call once generation is complete.
     GenerateMHTMLCallback callback;
   };
 
   MHTMLGenerationManager();
   virtual ~MHTMLGenerationManager();
 
   // Called on the file thread to create |file|.
   void CreateFile(int job_id,
                   const base::FilePath& file,
                   base::ProcessHandle renderer_process);
 
   // Called on the UI thread when the file that should hold the MHTML data has
   // been created.  This returns a handle to that file for the browser process
   // and one for the renderer process. These handles are
   // kInvalidPlatformFileValue if the file could not be opened.
-  void FileCreated(int job_id,
-                   base::PlatformFile browser_file,
-                   IPC::PlatformFileForTransit renderer_file);
+  void FileHandleAvailable(int job_id,
+                           base::PlatformFile browser_file,
+                           IPC::PlatformFileForTransit renderer_file);
 
   // Called on the file thread to close the file the MHTML was saved to.
   void CloseFile(base::PlatformFile file);
 
   // Called on the UI thread when a job has been processed (successfully or
   // not).  Closes the file and removes the job from the job map.
   // |mhtml_data_size| is -1 if the MHTML generation failed.
   void JobFinished(int job_id, int64 mhtml_data_size);
 
+  // Creates an register a new job.
+  int NewJob(WebContents* web_contents, const GenerateMHTMLCallback& callback);
+
   // Implementation of NotificationObserver.
   virtual void Observe(int type,
                        const NotificationSource& source,
                        const NotificationDetails& details) OVERRIDE;
 
   typedef std::map<int, Job> IDToJobMap;
   IDToJobMap id_to_job_;
   NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(MHTMLGenerationManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_MHTML_GENERATION_MANAGER_H_