Use ExternalFileSystemBackend in the DriveURLRequestJob.

chrome/browser/chromeos/drive/drive_url_request_job.h

Index: chrome/browser/chromeos/drive/drive_url_request_job.h
diff --git a/chrome/browser/chromeos/drive/drive_url_request_job.h b/chrome/browser/chromeos/drive/drive_url_request_job.h
index 661f3910f8f7b09cfc7a9f2d1599cef180338954..1b55b5a46424be32a8bad610ba6ee7565cd7aaa3 100644
--- a/chrome/browser/chromeos/drive/drive_url_request_job.h
+++ b/chrome/browser/chromeos/drive/drive_url_request_job.h
@@ -9,16 +9,12 @@
 
 #include "base/basictypes.h"
 #include "base/callback.h"
-#include "base/memory/ref_counted.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/chromeos/drive/file_errors.h"
 #include "net/http/http_byte_range.h"
 #include "net/url_request/url_request_job.h"
-
-namespace base {
-class SequencedTaskRunner;
-}  // namespace
+#include "storage/browser/blob/file_stream_reader.h"
+#include "storage/browser/fileapi/file_system_url.h"
 
 namespace net {
 class IOBuffer;
@@ -28,26 +24,13 @@ class URLRequest;
 
 namespace drive {
 
-class DriveFileStreamReader;
-class FileSystemInterface;
-class ResourceEntry;
-
 // DriveURLRequestJob is the gateway between network-level drive:...
 // requests for drive resources and FileSystem.  It exposes content URLs
 // formatted as drive:<drive-file-path>.
-// The methods should be run on IO thread, and the operations to communicate
-// with a locally cached file will run on |file_task_runner|.
+// The methods should be run on IO thread.
 class DriveURLRequestJob : public net::URLRequestJob {
  public:
-
-  // Callback to return the FileSystemInterface instance. This is an
-  // injecting point for testing.
-  // Note that the callback will be copied between threads (IO and UI), and
-  // will be called on UI thread.
-  typedef base::Callback<FileSystemInterface*()> FileSystemGetter;
-
-  DriveURLRequestJob(const FileSystemGetter& file_system_getter,
-                     base::SequencedTaskRunner* file_task_runner,
+  DriveURLRequestJob(void* profile_id,
                      net::URLRequest* request,
                      net::NetworkDelegate* network_delegate);
 
@@ -66,21 +49,35 @@ class DriveURLRequestJob : public net::URLRequestJob {
   virtual ~DriveURLRequestJob();
 
  private:
-  // Called when the initialization of DriveFileStreamReader is completed.
-  void OnDriveFileStreamReaderInitialized(
-      int error, scoped_ptr<ResourceEntry> entry);
+  class GetFileSystemContextDelegate;
+  typedef base::Callback<void(scoped_ptr<GetFileSystemContextDelegate>)>
+      DelegateCallback;
+
+  // Called after Start method.

[mtomasz, 2014/09/18 07:21:07]

OnGotDelegate -> OnDelegateObtained to be consistent with other methods below?

[hirono, 2014/09/18 08:18:55]

Done.

+  void OnGotDelegate(scoped_ptr<GetFileSystemContextDelegate> delegate);
+
+  // Called after OnGotDelegate method.

[mtomasz, 2014/09/18 07:21:07]

I think this comment is not very helpful. We should rather say which method is
invoking this callback.

[hirono, 2014/09/18 08:18:55]

Done.

+  void OnRedirectURLObtained(const GURL& redirect_url);
+
+  // Called after OnRedirectURLObtained method.
+  void OnFileInfoObtained(base::File::Error result,
+                          const base::File::Info& file_info);
+
+  // Called after OnFileInfoObtained method.
+  void OnMimeTypeObtained(const std::string& mime_type);
 
   // Called when DriveFileStreamReader::Read is completed.
   void OnReadCompleted(int read_result);
 
-  const FileSystemGetter file_system_getter_;
-  scoped_refptr<base::SequencedTaskRunner> file_task_runner_;
+  void* const profile_id_;
 
   // The range of the file to be returned.
   net::HttpByteRange byte_range_;
+  int total_bytes_read_;
 
-  scoped_ptr<DriveFileStreamReader> stream_reader_;
-  scoped_ptr<ResourceEntry> entry_;
+  scoped_ptr<GetFileSystemContextDelegate> delegate_;
+  scoped_ptr<storage::FileStreamReader> stream_reader_;
+  GURL redirect_url_;
 
   // This should remain the last member so it'll be destroyed first and
   // invalidate its weak pointers before other members are destroyed.