Initial implementation of the ByteStream refactor.

content/browser/download/download_resource_handler.h

Index: content/browser/download/download_resource_handler.h
diff --git a/content/browser/download/download_resource_handler.h b/content/browser/download/download_resource_handler.h
index 3a9a5c77e363e772d0d63bd6dac3684e30f80064..1ec581c4874628cca95abe70e9029f2342527dff 100644
--- a/content/browser/download/download_resource_handler.h
+++ b/content/browser/download/download_resource_handler.h
@@ -18,12 +18,13 @@
 #include "content/public/browser/global_request_id.h"
 #include "net/base/net_errors.h"
 
+class DataLoanIOBuffer;
 class DownloadFileManager;
 class DownloadRequestHandle;
 struct DownloadCreateInfo;
 
 namespace content {
-class DownloadBuffer;
+class ByteStream;
 }
 
 namespace net {
@@ -35,8 +36,6 @@ class DownloadResourceHandler : public ResourceHandler {
  public:
   typedef content::DownloadManager::OnStartedCallback OnStartedCallback;
 
-  static const size_t kLoadsToWrite = 100;  // number of data buffers queued
-
   // started_cb will be called exactly once on the UI thread.
   DownloadResourceHandler(int render_process_host_id,
                           int render_view_id,
@@ -87,8 +86,6 @@ class DownloadResourceHandler : public ResourceHandler {
 
   void set_content_disposition(const std::string& content_disposition);
 
-  void CheckWriteProgress();
-
   std::string DebugString() const;
 
  private:
@@ -99,7 +96,6 @@ class DownloadResourceHandler : public ResourceHandler {
                                    const std::string& security_info,
                                    int response_code);
 
-  void StartPauseTimer();
   void CallStartedCB(content::DownloadId id, net::Error error);
 
   // Generates a DownloadId and calls DownloadFileManager.
@@ -107,10 +103,12 @@ class DownloadResourceHandler : public ResourceHandler {
                        const DownloadRequestHandle& handle);
   void set_download_id(content::DownloadId id);
 
+  // Pause or resume the associated request as indicated by the output_pipe_.
+  void ThrottleRequest();
+
   content::DownloadId download_id_;
   content::GlobalRequestID global_id_;
   int render_view_id_;
-  scoped_refptr<net::IOBuffer> read_buffer_;
   std::string content_disposition_;
   int64 content_length_;
   DownloadFileManager* download_file_manager_;
@@ -118,10 +116,13 @@ class DownloadResourceHandler : public ResourceHandler {
   // This is used only on the UI thread.
   OnStartedCallback started_cb_;
   content::DownloadSaveInfo save_info_;
-  scoped_refptr<content::DownloadBuffer> buffer_;
-  bool is_paused_;
   base::OneShotTimer<DownloadResourceHandler> pause_timer_;
 
+  // Data flow
+  scoped_refptr<net::IOBuffer> read_buffer_;       // From URLRequest.
+  scoped_refptr<content::ByteStream> output_pipe_; // To rest of system.
+  bool is_paused_;
+
   // The following are used to collect stats.
   base::TimeTicks download_start_time_;
   base::TimeTicks last_read_time_;
@@ -129,6 +130,8 @@ class DownloadResourceHandler : public ResourceHandler {
   int64 bytes_read_;
   std::string accept_ranges_;
 
+  base::WeakPtrFactory<DownloadResourceHandler> weak_factory_;
+
   static const int kReadBufSize = 32768;  // bytes
   static const int kThrottleTimeMs = 200;  // milliseconds