[Page Load Metrics] Add mojom file to page load metrics.

chrome/browser/page_load_metrics/metrics_web_contents_observer.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/page_load_metrics/metrics_web_contents_observer.h"
 
 #include <algorithm>
 #include <ostream>
 #include <string>
 #include <utility>
@@ skipping 580 matching lines @@
     RecordInternalError(ERR_IPC_FROM_BAD_URL_SCHEME);
     error = true;
   }
 
   if (error)
     return;
 
   if (render_frame_host->GetParent() != nullptr) {
     // Child frames may send PageLoadMetadata updates, but not PageLoadTiming
     // updates.
-    if (!timing.IsEmpty())
+    if (!IsEmpty(timing))
       RecordInternalError(ERR_TIMING_IPC_FROM_SUBFRAME);
     committed_load_->UpdateChildFrameMetadata(metadata);
     return;
   }
 
   committed_load_->UpdateTiming(timing, metadata);
 
   for (auto& observer : testing_observers_)
     observer.OnTimingUpdated(true /* is_main_frame */, timing, metadata);
 }
@@ skipping 30 matching lines @@
     observer_->RemoveTestingObserver(this);
     observer_ = nullptr;
   }
 }
 
 void MetricsWebContentsObserver::TestingObserver::OnGoingAway() {
   observer_ = nullptr;
 }
 
 }  // namespace page_load_metrics