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

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

 // 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.
 
 #ifndef THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_RENDERER_RENDERER_SCHEDULER_IMPL_H_
 #define THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_RENDERER_RENDERER_SCHEDULER_IMPL_H_
 
 #include "base/atomicops.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/synchronization/lock.h"
 #include "base/trace_event/trace_log.h"
+#include "components/metrics/single_sample_metrics.h"
+#include "components/metrics/single_sample_metrics_factory_impl.h"

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

You can include the factory in the cc file, right? I don't think it's needed
here.

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

Done. We don't have to include factory. I include only the metric instead in my
patch.

 #include "device/base/synchronization/shared_memory_seqlock_buffer.h"
 #include "platform/scheduler/base/pollable_thread_safe_flag.h"
 #include "platform/scheduler/base/queueing_time_estimator.h"
 #include "platform/scheduler/base/task_time_observer.h"
 #include "platform/scheduler/base/thread_load_tracker.h"
 #include "platform/scheduler/child/idle_canceled_delayed_task_sweeper.h"
 #include "platform/scheduler/child/idle_helper.h"
 #include "platform/scheduler/child/scheduler_helper.h"
 #include "platform/scheduler/renderer/deadline_task_runner.h"
 #include "platform/scheduler/renderer/idle_time_estimator.h"
@@ skipping 460 matching lines @@
     bool timer_tasks_seem_expensive;
     bool touchstart_expected_soon;
     bool have_seen_a_begin_main_frame;
     bool have_reported_blocking_intervention_in_current_policy;
     bool have_reported_blocking_intervention_since_navigation;
     bool has_visible_render_widget_with_touch_handler;
     bool begin_frame_not_expected_soon;
     bool in_idle_period_for_testing;
     bool use_virtual_time;
     bool is_audio_playing;
+    bool during_navigation;

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

Add a comment about what it means to be "during_navigation".

The purpose of this attribute isn't clear to me. It looks like it's set to true
on the first OnNavigationStarted, and then is never set to false again?

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

Yes, we want to use this attribute to exclude those EQT before the navigation,
but this attribute includes EQT between the first navigation end and the next
navigation start that happens at the same thread, not sure whether it sounds
good to you? 

+    std::unique_ptr<base::SingleSampleMetric> max_queuing_time_histogram;
+    base::TimeDelta max_queuing_time;
     std::set<WebViewSchedulerImpl*> web_view_schedulers;  // Not owned.
     RAILModeObserver* rail_mode_observer;                 // Not owned.
     WakeUpBudgetPool* wake_up_budget_pool;                // Not owned.
     std::array<base::TimeDelta,
                static_cast<size_t>(TaskQueue::QueueType::COUNT)>
         unreported_task_duration;
     base::HistogramBase* task_duration_per_queue_type_histogram;
   };
 
   struct AnyThread {
@@ skipping 66 matching lines @@
 
   base::WeakPtrFactory<RendererSchedulerImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererSchedulerImpl);
 };
 
 }  // namespace scheduler
 }  // namespace blink
 
 #endif  // THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_RENDERER_RENDERER_SCHEDULER_IMPL_H_