[page_load_metrics] Add a NavigationThrottle for richer abort metrics

content/browser/frame_host/navigation_handle_impl.cc

Index: content/browser/frame_host/navigation_handle_impl.cc
diff --git a/content/browser/frame_host/navigation_handle_impl.cc b/content/browser/frame_host/navigation_handle_impl.cc
index 47dc9a23962c4e42ceaede2f50cd7418f4283fe0..0bc1ceb31c46c5a8bc6cfa7f0cd1684ed024c000 100644
--- a/content/browser/frame_host/navigation_handle_impl.cc
+++ b/content/browser/frame_host/navigation_handle_impl.cc
@@ -552,15 +552,16 @@ void NavigationHandleImpl::RegisterNavigationThrottles() {
   // RegisterThrottleForTesting.
   ScopedVector<NavigationThrottle> throttles_to_register =
       GetContentClient()->browser()->CreateThrottlesForNavigation(this);
+  std::unique_ptr<NavigationThrottle> devtools_throttle =
+      RenderFrameDevToolsAgentHost::CreateThrottleForNavigation(this);
+  if (devtools_throttle)
+    throttles_to_register.push_back(devtools_throttle.release());
+
   if (throttles_to_register.size() > 0) {
-    throttles_.insert(throttles_.end(), throttles_to_register.begin(),
+    throttles_.insert(throttles_.begin(), throttles_to_register.begin(),
                       throttles_to_register.end());
     throttles_to_register.weak_clear();
   }
-  std::unique_ptr<NavigationThrottle> devtools_throttle =
-      RenderFrameDevToolsAgentHost::CreateThrottleForNavigation(this);
-  if (devtools_throttle)
-    throttles_.push_back(devtools_throttle.release());
 }
 
 }  // namespace content