WIP: Implement 5xx Error handling.

chrome/browser/google_apis/drive_uploader.h

Index: chrome/browser/google_apis/drive_uploader.h
diff --git a/chrome/browser/google_apis/drive_uploader.h b/chrome/browser/google_apis/drive_uploader.h
index 4dc496b47f681d2e95727897fea4736d1f498287..22fdae13f343841812b2a8756cc4f4898edd9aa0 100644
--- a/chrome/browser/google_apis/drive_uploader.h
+++ b/chrome/browser/google_apis/drive_uploader.h
@@ -116,6 +116,11 @@ class DriveUploader : public DriveUploaderInterface {
                                 GDataErrorCode code,
                                 const GURL& upload_location);
 
+  // Uploads the remaining data in the current chunk.
+  // The |restart_position| is the file's position to be restart for uploading.
+  void UploadCurrentChunk(
+    scoped_ptr<UploadFileInfo> upload_file_info, int64 restart_position);
+
   // Uploads the next chunk of data from the file.
   void UploadNextChunk(scoped_ptr<UploadFileInfo> upload_file_info);
 
@@ -128,12 +133,23 @@ class DriveUploader : public DriveUploaderInterface {
   void ResumeUpload(scoped_ptr<UploadFileInfo> upload_file_info,
                     int bytes_to_send);
 
-  // DriveService callback for ResumeUpload.
+  // DriveService callback for ResumeUpload and GetUploadState.
   void OnResumeUploadResponseReceived(
       scoped_ptr<UploadFileInfo> upload_file_info,
       const ResumeUploadResponse& response,
       scoped_ptr<ResourceEntry> entry);
 
+  // Resumes the uploading interrupted by HTTP 5xx response.
+  // To avoid receiving the server errors repeatedly, this method waits
+  // for a while before actual resuming.
+  void ResumeInterruptedUpload(
+      scoped_ptr<UploadFileInfo> upload_file_info);
+
+  // This method processes the remaining tasks to resume the uploading
+  // after waiting followed by ResumeInterruptedUpload.
+  void ResumeInterruptedUploadAfterWaiting(
+      scoped_ptr<UploadFileInfo> upload_file_info);
+
   // Handle failed uploads.
   void UploadFailed(scoped_ptr<UploadFileInfo> upload_file_info,
                     DriveUploadError error);