Add GetChangelist operation for Drive V2.

chrome/browser/chromeos/gdata/gdata_documents_service.cc

Index: chrome/browser/chromeos/gdata/gdata_documents_service.cc
diff --git a/chrome/browser/chromeos/gdata/gdata_documents_service.cc b/chrome/browser/chromeos/gdata/gdata_documents_service.cc
index 7f1f27e26b6c1e95fca1eae17d992baefee90a24..355dd1937701cd6f2e4a0608d363ea86d895ac40 100644
--- a/chrome/browser/chromeos/gdata/gdata_documents_service.cc
+++ b/chrome/browser/chromeos/gdata/gdata_documents_service.cc
@@ -103,12 +103,24 @@ void DocumentsService::GetDocuments(const GURL& url,
 
   GetDocumentsOperation* operation =
       new GetDocumentsOperation(operation_registry(),
+                                url,
                                 start_changestamp,
                                 search_query,
                                 directory_resource_id,
                                 callback);
-  if (!url.is_empty())
-    operation->SetUrl(url);
+  runner_->StartOperationWithRetry(operation);
+}
+
+void DocumentsService::GetChangelist(const GURL& url,
+                                     int64 start_changestamp,
+                                     const GetDataCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  GetChangelistOperation* operation =
+      new GetChangelistOperation(operation_registry(),
+                                 url,
+                                 start_changestamp,
+                                 callback);
   runner_->StartOperationWithRetry(operation);
 }