Use defer out-params instead of ResourceDispatcherHostImpl::PauseRequest(...true)

content/browser/download/download_resource_handler.h

Index: content/browser/download/download_resource_handler.h
===================================================================
--- content/browser/download/download_resource_handler.h	(revision 136397)
+++ content/browser/download/download_resource_handler.h	(working copy)
@@ -60,7 +60,8 @@
 
   // Send the download creation information to the download thread.
   virtual bool OnResponseStarted(int request_id,
-                                 content::ResourceResponse* response) OVERRIDE;
+                                 content::ResourceResponse* response,
+                                 bool* defer) OVERRIDE;
 
   // Pass-through implementation.
   virtual bool OnWillStart(int request_id,
@@ -74,24 +75,20 @@
                           int* buf_size,
                           int min_size) OVERRIDE;
 
-  virtual bool OnReadCompleted(int request_id, int* bytes_read) OVERRIDE;
+  virtual bool OnReadCompleted(int request_id, int* bytes_read,
+                               bool* defer) OVERRIDE;
 
   virtual bool OnResponseCompleted(int request_id,
                                    const net::URLRequestStatus& status,
                                    const std::string& security_info) OVERRIDE;
   virtual void OnRequestClosed() OVERRIDE;
 
-  // If the content-length header is not present (or contains something other
-  // than numbers), the incoming content_length is -1 (unknown size).
-  // Set the content length to 0 to indicate unknown size to DownloadManager.
-  void set_content_length(const int64& content_length);
+  std::string DebugString() const;

[Randy Smith (Not in Mondays), 2012/05/18 20:17:02]

suggestion: My care factor isn't high, but I have a preference for DebugString()
being the last public method.

[darin (slow to review), 2012/05/18 23:09:05]

OK

 
-  void set_content_disposition(const std::string& content_disposition);
+  void PauseRequest();
+  void ResumeRequest();
+  void CancelRequest();
 
-  void CheckWriteProgress();
-
-  std::string DebugString() const;
-
  private:
   virtual ~DownloadResourceHandler();
 
@@ -100,14 +97,23 @@
                                    const std::string& security_info,
                                    int response_code);
 
-  void StartPauseTimer();
+  void CheckWriteProgressLater();
+  void CheckWriteProgress();
+  void MaybeResumeRequest();
   void CallStartedCB(content::DownloadId id, net::Error error);
 
   // Generates a DownloadId and calls DownloadFileManager.
   void StartOnUIThread(scoped_ptr<DownloadCreateInfo> info,
                        const DownloadRequestHandle& handle);
-  void set_download_id(content::DownloadId id);
+  void SetDownloadID(content::DownloadId id);
 
+  // If the content-length header is not present (or contains something other
+  // than numbers), the incoming content_length is -1 (unknown size).
+  // Set the content length to 0 to indicate unknown size to DownloadManager.
+  void SetContentLength(const int64& content_length);
+
+  void SetContentDisposition(const std::string& content_disposition);
+
   content::DownloadId download_id_;
   content::GlobalRequestID global_id_;
   int render_view_id_;
@@ -120,8 +126,7 @@
   OnStartedCallback started_cb_;
   content::DownloadSaveInfo save_info_;
   scoped_refptr<content::DownloadBuffer> buffer_;
-  bool is_paused_;
-  base::OneShotTimer<DownloadResourceHandler> pause_timer_;
+  base::OneShotTimer<DownloadResourceHandler> check_write_progress_timer_;
 
   // The following are used to collect stats.
   base::TimeTicks download_start_time_;
@@ -130,6 +135,9 @@
   int64 bytes_read_;
   std::string accept_ranges_;
 
+  int pause_count_;

[Randy Smith (Not in Mondays), 2012/05/18 20:17:02]

nit: Small comment ahead of these describing the state machine they implement?  

+  bool was_deferred_;
+
   static const int kReadBufSize = 32768;  // bytes
   static const int kThrottleTimeMs = 200;  // milliseconds