[Page Load Metrics] PageLoadMetrics Mojofication.

chrome/renderer/page_load_metrics/page_timing_metrics_sender.cc

Index: chrome/renderer/page_load_metrics/page_timing_metrics_sender.cc
diff --git a/chrome/renderer/page_load_metrics/page_timing_metrics_sender.cc b/chrome/renderer/page_load_metrics/page_timing_metrics_sender.cc
index e016bb3251445b98216fb664624a3b9a22bd3572..1fa66beaf49fd587dc234db8bb34e35505cbff0c 100644
--- a/chrome/renderer/page_load_metrics/page_timing_metrics_sender.cc
+++ b/chrome/renderer/page_load_metrics/page_timing_metrics_sender.cc
@@ -7,9 +7,12 @@
 #include <utility>
 
 #include "base/callback.h"
+#include "base/feature_list.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
+#include "chrome/common/chrome_features.h"
 #include "chrome/common/page_load_metrics/page_load_metrics_messages.h"
+#include "chrome/renderer/page_load_metrics/page_timing_sender.h"
 #include "ipc/ipc_sender.h"
 
 namespace page_load_metrics {
@@ -22,10 +25,12 @@ const int kTimerDelayMillis = 1000;
 PageTimingMetricsSender::PageTimingMetricsSender(
     IPC::Sender* ipc_sender,
     int routing_id,
+    PageTimingSender* page_timing_sender,
     std::unique_ptr<base::Timer> timer,
     const PageLoadTiming& initial_timing)
     : ipc_sender_(ipc_sender),
       routing_id_(routing_id),
+      page_timing_sender_(page_timing_sender),
       timer_(std::move(timer)),
       last_timing_(initial_timing),
       metadata_(PageLoadMetadata()) {
@@ -76,6 +81,10 @@ void PageTimingMetricsSender::EnsureSendTimer(int delay) {
 }
 
 void PageTimingMetricsSender::SendNow() {
+  if (base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication)) {
+    page_timing_sender_->SendTiming(last_timing_, metadata_);

[Zhen Wang, 2017/04/19 18:49:54]

So this actually calls to MetricsRenderFrameObserver::SendTiming(). Can we just
do the following?

page_load_metrics_->UpdateTiming(timing, metadata);

We can also just get the mojo end point here.

+    return;
+  }
   ipc_sender_->Send(new PageLoadMetricsMsg_TimingUpdated(

[Zhen Wang, 2017/04/19 18:56:31]

We do not need to always send this via IPC. The flag can just toggle this:
either send via IPC or Mojo, but not both. So the IPC one is control group and
the Mojo one is experiment group. This can simplify the code on the browser
side.

       routing_id_, last_timing_, metadata_));
 }