Add UKM for peak windowed percent usage by ad frames.

This CL adds the PeakWindowedUsage metric to AdFrameLoad UKM. This can
be used alongside the existing CpuTime metrics to better determine the
type of ads with high CPU usage.

Bug: 978030
Change-Id: I4175c87d149003b040260a837c2a5de3e2ca1633
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1653390Reviewed-by: Steven Holte <holte@chromium.org>
Reviewed-by: John Delaney <johnidel@chromium.org>
Reviewed-by: Josh Karlin <jkarlin@chromium.org>
Commit-Queue: John Delaney <johnidel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#680004}

chrome/browser/page_load_metrics/observers/ad_metrics/ads_page_load_metrics_observer_unittest.cc

@@ -1128,6 +1128,10 @@ TEST_F(AdsPageLoadMetricsObserverTest, TestCpuTimingMetrics) {
   EXPECT_EQ(1u, entries.size());
   test_ukm_recorder().ExpectEntryMetric(
       entries.front(), ukm::builders::AdFrameLoad::kCpuTime_TotalName, 1500);
+  test_ukm_recorder().ExpectEntryMetric(
+      entries.front(),
+      ukm::builders::AdFrameLoad::kCpuTime_PeakWindowedPercentName,
+      100 * 1500 / 30000);
   EXPECT_FALSE(test_ukm_recorder().EntryHasMetric(
       entries.front(), ukm::builders::AdFrameLoad::kCpuTime_PreActivationName));
   EXPECT_FALSE(test_ukm_recorder().EntryHasMetric(
@@ -1182,6 +1186,10 @@ TEST_F(AdsPageLoadMetricsObserverTest,
   EXPECT_EQ(1u, entries.size());
   test_ukm_recorder().ExpectEntryMetric(
       entries.front(), ukm::builders::AdFrameLoad::kCpuTime_TotalName, 1500);
+  test_ukm_recorder().ExpectEntryMetric(
+      entries.front(),
+      ukm::builders::AdFrameLoad::kCpuTime_PeakWindowedPercentName,
+      100 * 1500 / 30000);
   EXPECT_FALSE(test_ukm_recorder().EntryHasMetric(
       entries.front(), ukm::builders::AdFrameLoad::kCpuTime_PreActivationName));
   EXPECT_FALSE(test_ukm_recorder().EntryHasMetric(
@@ -1239,6 +1247,10 @@ TEST_F(AdsPageLoadMetricsObserverTest, TestCpuTimingMetricsOnActivation) {
   EXPECT_EQ(1u, entries.size());
   test_ukm_recorder().ExpectEntryMetric(
       entries.front(), ukm::builders::AdFrameLoad::kCpuTime_TotalName, 1500);
+  test_ukm_recorder().ExpectEntryMetric(
+      entries.front(),
+      ukm::builders::AdFrameLoad::kCpuTime_PeakWindowedPercentName,
+      100 * 1000 / 30000);
   test_ukm_recorder().ExpectEntryMetric(
       entries.front(), ukm::builders::AdFrameLoad::kCpuTime_PreActivationName,
       1000);
@@ -1293,6 +1305,9 @@ TEST_F(AdsPageLoadMetricsObserverTest, TestNoReportingWhenAlwaysBackgrounded) {
   EXPECT_EQ(1u, entries.size());
   test_ukm_recorder().ExpectEntryMetric(
       entries.front(), ukm::builders::AdFrameLoad::kCpuTime_TotalName, 0);
+  test_ukm_recorder().ExpectEntryMetric(
+      entries.front(),
+      ukm::builders::AdFrameLoad::kCpuTime_PeakWindowedPercentName, 0);
   EXPECT_FALSE(test_ukm_recorder().EntryHasMetric(
       entries.front(), ukm::builders::AdFrameLoad::kCpuTime_PreActivationName));
   EXPECT_FALSE(test_ukm_recorder().EntryHasMetric(
@@ -1330,6 +1345,10 @@ TEST_F(AdsPageLoadMetricsObserverTest, TestCpuTimingMetricsNoInteractive) {
   EXPECT_EQ(1u, entries.size());
   test_ukm_recorder().ExpectEntryMetric(
       entries.front(), ukm::builders::AdFrameLoad::kCpuTime_TotalName, 500);
+  test_ukm_recorder().ExpectEntryMetric(
+      entries.front(),
+      ukm::builders::AdFrameLoad::kCpuTime_PeakWindowedPercentName,
+      100 * 500 / 30000);
 }
 
 TEST_F(AdsPageLoadMetricsObserverTest, TestCpuTimingMetricsShortTimeframes) {
@@ -1373,6 +1392,10 @@ TEST_F(AdsPageLoadMetricsObserverTest, TestCpuTimingMetricsShortTimeframes) {
   EXPECT_EQ(1u, entries.size());
   test_ukm_recorder().ExpectEntryMetric(
       entries.front(), ukm::builders::AdFrameLoad::kCpuTime_TotalName, 1500);
+  test_ukm_recorder().ExpectEntryMetric(
+      entries.front(),
+      ukm::builders::AdFrameLoad::kCpuTime_PeakWindowedPercentName,
+      100 * 1500 / 30000);
 }
 
 TEST_F(AdsPageLoadMetricsObserverTest, AdFrameLoadTiming) {

chrome/browser/page_load_metrics/observers/ad_metrics/frame_data.cc

@@ -248,6 +248,8 @@ void FrameData::RecordAdFrameLoadUkmEvent(ukm::SourceId source_id) const {
         pre_activation_foreground_duration().InMilliseconds());
   }
 
+  builder.SetCpuTime_PeakWindowedPercent(peak_windowed_cpu_percent_);
+
   builder
       .SetVisibility_FrameWidth(
           ukm::GetExponentialBucketMinForCounts1000(frame_size().width()))

tools/metrics/ukm/ukm.xml

@@ -89,6 +89,13 @@ be describing additional metrics about the same event.
     with non-zero bytes. Recorded when a page is destroyed or when the app is
     backgrounded on mobile.
   </summary>
+  <metric name="CpuTime.PeakWindowedPercent">
+    <summary>
+      The peak percentage of CPU utilization attributed to the frame in any 30
+      second window prior to user activation. Frames that exist for less than 30
+      seconds still use 30 seconds as the denominator for the calculation.
+    </summary>
+  </metric>
   <metric name="CpuTime.PreActivation">
     <summary>
       Wall time of tasks attributed to the frame after the frame recieved user