Revert 154294 - Remove DownloadFileManager in favor of direct ownership of DownloadFiles.

content/browser/download/download_file.h

Index: content/browser/download/download_file.h
===================================================================
--- content/browser/download/download_file.h	(revision 154444)
+++ content/browser/download/download_file.h	(working copy)
@@ -11,6 +11,7 @@
 #include "base/callback_forward.h"
 #include "base/file_path.h"
 #include "content/common/content_export.h"
+#include "content/public/browser/download_id.h"
 #include "content/public/browser/download_interrupt_reasons.h"
 
 namespace content {
@@ -23,12 +24,6 @@
 // cancelled, the DownloadFile is destroyed.
 class CONTENT_EXPORT DownloadFile {
  public:
-  // Callback used with Initialize.  On a successful initialize, |reason| will
-  // be DOWNLOAD_INTERRUPT_REASON_NONE; on a failed initialize, it will be
-  // set to the reason for the failure.
-  typedef base::Callback<void(content::DownloadInterruptReason reason)>
-      InitializeCallback;
-
   // Callback used with Rename().  On a successful rename |reason| will be
   // DOWNLOAD_INTERRUPT_REASON_NONE and |path| the path the rename
   // was done to.  On a failed rename, |reason| will contain the
@@ -38,10 +33,10 @@
 
   virtual ~DownloadFile() {}
 
+  // If calculate_hash is true, sha256 hash will be calculated.
   // Returns DOWNLOAD_INTERRUPT_REASON_NONE on success, or a network
-  // error code on failure.  Upon completion, |callback| will be
-  // called on the UI thread as per the comment above.
-  virtual void Initialize(const InitializeCallback& callback) = 0;
+  // error code on failure.
+  virtual DownloadInterruptReason Initialize() = 0;
 
   // Rename the download file to |full_path|.  If that file exists and
   // |overwrite_existing_file| is false, |full_path| will be uniquified by
@@ -73,11 +68,14 @@
   // Returns the current (intermediate) state of the hash as a byte string.
   virtual std::string GetHashState() = 0;
 
-  // For testing.  Must be called on FILE thread.
-  static int GetNumberOfDownloadFiles();
+  // Cancels the download request associated with this file.
+  virtual void CancelDownloadRequest() = 0;
 
- protected:
-  static int number_active_objects_;
+  virtual int Id() const = 0;
+  virtual DownloadManager* GetDownloadManager() = 0;
+  virtual const DownloadId& GlobalId() const = 0;
+
+  virtual std::string DebugString() const = 0;
 };
 
 }  // namespace content