Make PageLoadMetricsWaiter more resilient

chrome/browser/page_load_metrics/page_load_metrics_update_dispatcher.cc

 // Copyright 2017 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/page_load_metrics_update_dispatcher.h"
 
 #include <ostream>
 #include <utility>
 
 #include "base/logging.h"
@@ skipping 282 matching lines @@
 void PageLoadMetricsUpdateDispatcher::UpdateSubFrameTiming(
     content::RenderFrameHost* render_frame_host,
     const mojom::PageLoadTiming& new_timing) {
   const auto it = subframe_navigation_start_offset_.find(
       render_frame_host->GetFrameTreeNodeId());
   if (it == subframe_navigation_start_offset_.end()) {
     // We received timing information for an untracked load. Ignore it.
     return;
   }
 
+  client_->OnSubFrameTimingChanged(new_timing);
+
   base::TimeDelta navigation_start_offset = it->second;
   MergePaintTiming(navigation_start_offset, *(new_timing.paint_timing),
                    false /* is_main_frame */);
 
   DispatchTimingUpdates();
 }
 
 void PageLoadMetricsUpdateDispatcher::MergePaintTiming(
     base::TimeDelta navigation_start_offset,
     const mojom::PaintTiming& new_paint_timing,
@@ skipping 107 matching lines @@
 
   internal::PageLoadTimingStatus status =
       IsValidPageLoadTiming(*pending_merged_page_timing_);
   UMA_HISTOGRAM_ENUMERATION(internal::kPageLoadTimingDispatchStatus, status,
                             internal::LAST_PAGE_LOAD_TIMING_STATUS);
 
   client_->OnTimingChanged();
 }
 
 }  // namespace page_load_metrics