Report page load timing information for child frames.

chrome/renderer/page_load_metrics/page_timing_metrics_sender.cc

 // Copyright 2015 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 "chrome/renderer/page_load_metrics/page_timing_metrics_sender.h"
 
 #include <utility>
 
 #include "base/callback.h"
 #include "base/time/time.h"
@@ skipping 12 matching lines @@
     IPC::Sender* ipc_sender,
     int routing_id,
     std::unique_ptr<base::Timer> timer,
     const PageLoadTiming& initial_timing)
     : ipc_sender_(ipc_sender),
       routing_id_(routing_id),
       timer_(std::move(timer)),
       last_timing_(initial_timing),
       metadata_(PageLoadMetadata()) {
   if (!initial_timing.IsEmpty()) {
-    // Send an initial IPC relatively early to help track aborts.
-    EnsureSendTimer(kInitialTimerDelayMillis);
+    EnsureSendTimer();
   }
 }
 
 // On destruction, we want to send any data we have if we have a timer
 // currently running (and thus are talking to a browser process)
 PageTimingMetricsSender::~PageTimingMetricsSender() {
   if (timer_->IsRunning()) {
     timer_->Stop();
     SendNow();
   }
 }
 
 void PageTimingMetricsSender::DidObserveLoadingBehavior(
     blink::WebLoadingBehaviorFlag behavior) {
   if (behavior & metadata_.behavior_flags)
     return;
   metadata_.behavior_flags |= behavior;
-  EnsureSendTimer(kTimerDelayMillis);
+  EnsureSendTimer();
 }
 
 void PageTimingMetricsSender::Send(const PageLoadTiming& timing) {
   if (timing == last_timing_)
     return;
 
   // We want to make sure that each PageTimingMetricsSender is associated
   // with a distinct page navigation. Because we reset the object on commit,
   // we can trash last_timing_ on a provisional load before SendNow() fires.
   if (!last_timing_.navigation_start.is_null() &&
       last_timing_.navigation_start != timing.navigation_start) {
     return;
   }
 
   last_timing_ = timing;
-  EnsureSendTimer(kTimerDelayMillis);
+  EnsureSendTimer();
 }
 
-void PageTimingMetricsSender::EnsureSendTimer(int delay) {
-  if (!timer_->IsRunning())
+void PageTimingMetricsSender::EnsureSendTimer() {
+  if (!timer_->IsRunning()) {
+    // Send the first IPC eagerly to make sure the receiving side knows we're
+    // sending metrics as soon as possible.
+    int delay_ms =
+        have_sent_ipc_ ? kTimerDelayMillis : kInitialTimerDelayMillis;
     timer_->Start(
-        FROM_HERE, base::TimeDelta::FromMilliseconds(delay),
+        FROM_HERE, base::TimeDelta::FromMilliseconds(delay_ms),
         base::Bind(&PageTimingMetricsSender::SendNow, base::Unretained(this)));
+  }
 }
 
 void PageTimingMetricsSender::SendNow() {
+  have_sent_ipc_ = true;
   ipc_sender_->Send(new PageLoadMetricsMsg_TimingUpdated(
       routing_id_, last_timing_, metadata_));
 }
 
 }  // namespace page_load_metrics