Reland "Revert 156830 - drive: Stop exposing operation_registry() from DriveServiceInterface"

chrome/browser/chromeos/gdata/drive_service_interface.h

Index: chrome/browser/chromeos/gdata/drive_service_interface.h
diff --git a/chrome/browser/chromeos/gdata/drive_service_interface.h b/chrome/browser/chromeos/gdata/drive_service_interface.h
index a9d6ae194e64f8e3bb22e29a2847cb62ffe0f5e3..bc55152a59cb0f5b3e2140dd4e12a39f051d7f09 100644
--- a/chrome/browser/chromeos/gdata/drive_service_interface.h
+++ b/chrome/browser/chromeos/gdata/drive_service_interface.h
@@ -45,7 +45,13 @@ enum DocumentExportFormat {
 class DriveServiceObserver {
  public:
   // Triggered when the service gets ready to perform operations.
-  virtual void OnReadyToPerformOperations() = 0;
+  virtual void OnReadyToPerformOperations() {}
+
+  // Called when an operation started, made some progress, or finished.
+  virtual void OnProgressUpdate(const OperationProgressStatusList& list) {}
+
+  // Called when GData authentication failed.
+  virtual void OnAuthenticationFailed() {}
 
  protected:
   virtual ~DriveServiceObserver() {}
@@ -74,15 +80,19 @@ class DriveServiceInterface {
   // Removes an observer.
   virtual void RemoveObserver(DriveServiceObserver* observer) = 0;
 
-  // Retrieves the operation registry.
-  virtual OperationRegistry* operation_registry() const = 0;
-
   // True if ready to start operations.
   virtual bool CanStartOperation() const = 0;
 
   // Cancels all in-flight operations.
   virtual void CancelAll() = 0;
 
+  // Cancels ongoing operation for a given virtual |file_path|. Returns true if
+  // the operation was found and canceled.
+  virtual bool CancelForFilePath(const FilePath& file_path) = 0;
+
+  // Obtains the list of currently active operations.
+  virtual OperationProgressStatusList GetProgressStatusList() const = 0;
+
   // Authentication service:
 
   // Authenticates the user by fetching the auth token as