EQT: Record the max queueing time from navigation start to navigation away

third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc

 // Copyright 2014 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 "platform/scheduler/renderer/renderer_scheduler_impl.h"
 
 #include "base/bind.h"
 #include "base/debug/stack_trace.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
@@ skipping 199 matching lines @@
       timer_tasks_seem_expensive(false),
       touchstart_expected_soon(false),
       have_seen_a_begin_main_frame(false),
       have_reported_blocking_intervention_in_current_policy(false),
       have_reported_blocking_intervention_since_navigation(false),
       has_visible_render_widget_with_touch_handler(false),
       begin_frame_not_expected_soon(false),
       in_idle_period_for_testing(false),
       use_virtual_time(false),
       is_audio_playing(false),
+      during_navigation(false),
       rail_mode_observer(nullptr),
       wake_up_budget_pool(nullptr),
       task_duration_per_queue_type_histogram(base::Histogram::FactoryGet(
           "RendererScheduler.TaskDurationPerQueueType",
           1,
           static_cast<int>(TaskQueue::QueueType::COUNT),
           static_cast<int>(TaskQueue::QueueType::COUNT) + 1,
           base::HistogramBase::kUmaTargetedHistogramFlag)) {
   foreground_main_thread_load_tracker.Resume(now);
 }
@@ skipping 1398 matching lines @@
       GetMainThreadOnly().navigation_task_expected_count > 0) {
     GetMainThreadOnly().navigation_task_expected_count--;
     UpdatePolicy();
   }
 }
 
 void RendererSchedulerImpl::OnNavigationStarted() {
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
                "RendererSchedulerImpl::OnNavigationStarted");
   base::AutoLock lock(any_thread_lock_);
+  GetMainThreadOnly().during_navigation = true;
   ResetForNavigationLocked();
 }
 
 void RendererSchedulerImpl::OnFirstMeaningfulPaint() {
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
                "RendererSchedulerImpl::OnFirstMeaningfulPaint");
   base::AutoLock lock(any_thread_lock_);
   GetAnyThread().waiting_for_meaningful_paint = false;
   UpdatePolicyLocked(UpdateType::MAY_EARLY_OUT_IF_POLICY_UNCHANGED);
 }
@@ skipping 25 matching lines @@
   GetAnyThread().user_model.Reset(helper_.scheduler_tqm_delegate()->NowTicks());
   GetAnyThread().have_seen_a_potentially_blocking_gesture = false;
   GetAnyThread().waiting_for_meaningful_paint = true;
   GetAnyThread().have_seen_input_since_navigation = false;
   GetMainThreadOnly().loading_task_cost_estimator.Clear();
   GetMainThreadOnly().timer_task_cost_estimator.Clear();
   GetMainThreadOnly().idle_time_estimator.Clear();
   GetMainThreadOnly().have_seen_a_begin_main_frame = false;
   GetMainThreadOnly().have_reported_blocking_intervention_since_navigation =
       false;
+  GetMainThreadOnly().max_queuing_time_histogram.reset();
+  GetMainThreadOnly().max_queuing_time = base::TimeDelta();
+
   for (WebViewSchedulerImpl* web_view_scheduler :
        GetMainThreadOnly().web_view_schedulers) {
     web_view_scheduler->OnNavigation();
   }
   UpdatePolicyLocked(UpdateType::MAY_EARLY_OUT_IF_POLICY_UNCHANGED);
 }
 
 void RendererSchedulerImpl::SetTopLevelBlameContext(
     base::trace_event::BlameContext* blame_context) {
   // Any task that runs in the default task runners belongs to the context of
@@ skipping 204 matching lines @@
 }
 
 void RendererSchedulerImpl::RemoveTaskTimeObserver(
     TaskTimeObserver* task_time_observer) {
   helper_.RemoveTaskTimeObserver(task_time_observer);
 }
 
 void RendererSchedulerImpl::OnQueueingTimeForWindowEstimated(
     base::TimeDelta queueing_time,
     base::TimeTicks window_start_time) {
+  if (GetMainThreadOnly().during_navigation) {
+    if (!GetMainThreadOnly().max_queuing_time_histogram) {

[tdresser, 2017/05/23 14:57:51]

Add a comment about why we're instantiating this here.

[Liquan (Max) Gu, 2017/05/25 16:27:28]

Done.

+      GetMainThreadOnly().max_queuing_time_histogram =
+          base::SingleSampleMetricsFactory::Get()->CreateCustomCountsMetric(
+              "RendererScheduler.MaxQueueingTime", 1, 10000, 50);
+    }
+    if (GetMainThreadOnly().max_queuing_time < queueing_time) {
+      GetMainThreadOnly().max_queuing_time_histogram->SetSample(
+          GetMainThreadOnly().max_queuing_time.InMilliseconds());
+      GetMainThreadOnly().max_queuing_time = queueing_time;
+    }
+  }
   // RendererScheduler reports the queueing time once per window's duration.
   //          |stepEQT|stepEQT|stepEQT|stepEQT|stepEQT|stepEQT|
   // Report:  |-------window EQT------|
   // Discard:         |-------window EQT------|
   // Discard:                 |-------window EQT------|
   // Report:                          |-------window EQT------|
   if (window_start_time -
           GetMainThreadOnly().uma_last_queueing_time_report_window_start_time <
       kQueueingTimeWindowDuration) {
     return;
@@ skipping 137 matching lines @@
     case TimeDomainType::VIRTUAL:
       return "virtual";
     default:
       NOTREACHED();
       return nullptr;
   }
 }
 
 }  // namespace scheduler
 }  // namespace blink