drive: Deal with the root directory in the same way as others in MoveOperation.

chrome/browser/google_apis/fake_drive_service.cc

Index: chrome/browser/google_apis/fake_drive_service.cc
diff --git a/chrome/browser/google_apis/fake_drive_service.cc b/chrome/browser/google_apis/fake_drive_service.cc
index 8c7d086410a851c2aef1c8d343fbc7e7f26e0483..e7538bc767943d78cda6cd6384287815fcb443f3 100644
--- a/chrome/browser/google_apis/fake_drive_service.cc
+++ b/chrome/browser/google_apis/fake_drive_service.cc
@@ -578,6 +578,14 @@ void FakeDriveService::RemoveResourceFromDirectory(
           return;
         }
       }
+
+      // We are dealing with a no-"parent"-link file as in the root directory.
+      if (parent_content_url.is_empty()) {
+        AddNewChangestamp(entry);
+        MessageLoop::current()->PostTask(
+            FROM_HERE, base::Bind(callback, HTTP_SUCCESS));
+        return;
+      }
     }
   }