Temporarily disable error detection for response_start.

chrome/browser/page_load_metrics/page_load_tracker.cc

 // Copyright 2016 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_tracker.h"
 
 #include <algorithm>
 #include <ostream>
 #include <string>
 #include <utility>
@@ skipping 127 matching lines @@
     return internal::INVALID_NULL_NAVIGATION_START;
   }
 
   // Verify proper ordering between the various timings.
 
   if (!EventsInOrder(timing.response_start, timing.parse_timing.parse_start)) {
     // We sometimes get a zero response_start with a non-zero parse start. See
     // crbug.com/590212.
     LOG(ERROR) << "Invalid response_start " << timing.response_start
                << " for parse_start " << timing.parse_timing.parse_start;
-    return internal::INVALID_ORDER_RESPONSE_START_PARSE_START;
+    // When browser-side navigation is enabled, we sometimes encounter this
+    // error case. For now, we disable reporting of this error, since most
+    // PageLoadMetricsObservers don't care about response_start and we want to
+    // see how much closer fixing this error will get us to page load metrics
+    // being consistent with and without browser side navigation enabled. See
+    // crbug.com/716587 for more details.
+    //
+    // return internal::INVALID_ORDER_RESPONSE_START_PARSE_START;
   }
 
   if (!EventsInOrder(timing.parse_timing.parse_start,
                      timing.parse_timing.parse_stop)) {
     LOG(ERROR) << "Invalid parse_start " << timing.parse_timing.parse_start
                << " for parse_stop " << timing.parse_timing.parse_stop;
     return internal::INVALID_ORDER_PARSE_START_PARSE_STOP;
   }
 
   if (timing.parse_timing.parse_stop) {
@@ skipping 645 matching lines @@
     observer->MediaStartedPlaying(video_type, is_in_main_frame);
 }
 
 void PageLoadTracker::OnNavigationDelayComplete(base::TimeDelta scheduled_delay,
                                                 base::TimeDelta actual_delay) {
   for (const auto& observer : observers_)
     observer->OnNavigationDelayComplete(scheduled_delay, actual_delay);
 }
 
 }  // namespace page_load_metrics