Skip page refresh navigation in navigation observer

chrome/browser/safe_browsing/safe_browsing_navigation_observer_manager.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/safe_browsing/safe_browsing_navigation_observer_manager.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/stringprintf.h"
 #include "base/time/time.h"
@@ skipping 157 matching lines @@
         nav_event->target_tab_id == target_tab_id &&
         nav_event->source_tab_id != nav_event->target_tab_id) {
       return nav_event;
     }
   }
   return nullptr;
 }
 
 void NavigationEventList::RecordNavigationEvent(
     std::unique_ptr<NavigationEvent> nav_event) {
+  // Skip page refresh.
+  if (nav_event->source_url == nav_event->GetDestinationUrl() &&
+      nav_event->source_tab_id == nav_event->target_tab_id)
+    return;
+
   if (navigation_events_.size() == size_limit_)
     navigation_events_.pop_front();
   navigation_events_.push_back(std::move(nav_event));
 }
 
 std::size_t NavigationEventList::CleanUpNavigationEvents() {
   // Remove any stale NavigationEnvent, if it is older than
   // kNavigationFootprintTTLInSecond.
   std::size_t removal_count = 0;
   while (navigation_events_.size() > 0 &&
@@ skipping 416 matching lines @@
             out_result));
     // Stop searching if the size of out_referrer_chain already reached its
     // limit.
     if (out_referrer_chain->size() == kReferrerChainMaxLength)
       return;
     last_main_frame_url_traced = last_nav_event_traced->source_main_frame_url;
   }
 }
 
 }  // namespace safe_browsing