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

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

Index: third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.h
diff --git a/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.h b/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.h
index 06d370b91b3b4bd20329df0e27299ddaada5815a..f176bc39732fa7e8d96c39cc8539756e37c3eeaa 100644
--- a/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.h
+++ b/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.h
@@ -12,6 +12,8 @@
 #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"
@@ -492,6 +494,9 @@ class PLATFORM_EXPORT RendererSchedulerImpl
     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.