Improve subframe navigation tracking.

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 295 matching lines @@
 }
 
 const PageLoadExtraInfo
 MetricsWebContentsObserver::GetPageLoadExtraInfoForCommittedLoad() {
   DCHECK(committed_load_);
   return committed_load_->ComputePageLoadExtraInfo();
 }
 
 void MetricsWebContentsObserver::DidFinishNavigation(
     content::NavigationHandle* navigation_handle) {
-  if (!navigation_handle->IsInMainFrame() && committed_load_) {
-    committed_load_->DidFinishSubFrameNavigation(navigation_handle);
+  if (!navigation_handle->IsInMainFrame()) {
+    if (committed_load_ && navigation_handle->GetParentFrame() &&
+        GetMainFrame(navigation_handle->GetParentFrame()) ==
+            web_contents()->GetMainFrame()) {
+      committed_load_->DidFinishSubFrameNavigation(navigation_handle);
+    }
     return;
   }
 
   std::unique_ptr<PageLoadTracker> finished_nav(
       std::move(provisional_loads_[navigation_handle]));
   provisional_loads_.erase(navigation_handle);
 
   // Ignore same-document navigations.
   if (navigation_handle->HasCommitted() &&
       navigation_handle->IsSameDocument()) {
@@ skipping 314 matching lines @@
     observer_->RemoveTestingObserver(this);
     observer_ = nullptr;
   }
 }
 
 void MetricsWebContentsObserver::TestingObserver::OnGoingAway() {
   observer_ = nullptr;
 }
 
 }  // namespace page_load_metrics