Replace FileResource::set_labels with mutable_labels

chrome/browser/google_apis/drive_api_parser.h

Index: chrome/browser/google_apis/drive_api_parser.h
diff --git a/chrome/browser/google_apis/drive_api_parser.h b/chrome/browser/google_apis/drive_api_parser.h
index 7c23f24b1f2bc40479da160c152284cdb971d412..140834ed69c27316fc0fd63ed9d14bfebc516b1d 100644
--- a/chrome/browser/google_apis/drive_api_parser.h
+++ b/chrome/browser/google_apis/drive_api_parser.h
@@ -567,8 +567,8 @@ class FileResource {
   void set_mime_type(const std::string& mime_type) {
     mime_type_ = mime_type;
   }
-  void set_labels(const FileLabels& labels) {
-    labels_ = labels;
+  FileLabels* mutable_labels() {
+    return &labels_;
   }
   void set_created_date(const base::Time& created_date) {
     created_date_ = created_date;