[page_load_metrics] Log ParseDuration variants based on % cached subr…

…esources This patch uses the experimental page_load_metrics infrastructure which calculates % of cached subresources to separate out warm/cold cache page loads. BUG= Review-Url: https://codereview.chromium.org/2240553002 Cr-Commit-Position: refs/heads/master@{#411392}
Denger-Network · Aug 11, 2016 · 9cae2a0 · 9cae2a0
1 parent a83f2f3
commit 9cae2a0
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Showing 2 changed files with 32 additions and 3 deletions.
diff --git a/chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer.cc b/chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer.cc
@@ -399,13 +399,24 @@ void CorePageLoadMetricsObserver::OnParseStop(
 
     int total_requests = info.num_cache_requests + info.num_network_requests;
     if (total_requests) {
-      UMA_HISTOGRAM_PERCENTAGE(
-          internal::kHistogramCacheRequestPercentParseStop,
-          (100 * info.num_cache_requests) / total_requests);
+      int percent_cached = (100 * info.num_cache_requests) / total_requests;
+      UMA_HISTOGRAM_PERCENTAGE(internal::kHistogramCacheRequestPercentParseStop,
+                               percent_cached);
       UMA_HISTOGRAM_COUNTS(internal::kHistogramCacheTotalRequestsParseStop,
                            info.num_cache_requests);
       UMA_HISTOGRAM_COUNTS(internal::kHistogramTotalRequestsParseStop,
                            info.num_cache_requests + info.num_network_requests);
+
+      // Separate out parse duration based on cache percent.
+      if (percent_cached <= 50) {
+        PAGE_LOAD_HISTOGRAM(
+            "PageLoad.Experimental.ParseDuration.CachedPercent.0-50",
+            parse_duration);
+      } else {
+        PAGE_LOAD_HISTOGRAM(
+            "PageLoad.Experimental.ParseDuration.CachedPercent.51-100",
+            parse_duration);
+      }
     }
 
   } else {

diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
@@ -38124,6 +38124,24 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="PageLoad.Experimental.ParseDuration.CachePercent.0-50"
+    units="ms">
+  <owner>csharrison@chromium.org</owner>
+  <summary>
+    The parse duration of the page load where 0-50% of all subresources (loaded
+    during parsing) were served from the HTTP cache (including 304s).
+  </summary>
+</histogram>
+
+<histogram name="PageLoad.Experimental.ParseDuration.CachePercent.51-100"
+    units="ms">
+  <owner>csharrison@chromium.org</owner>
+  <summary>
+    The parse duration of the page load where 51-100% of all subresources
+    (loaded during parsing) were served from the HTTP cache (including 304s).
+  </summary>
+</histogram>
+
 <histogram name="PageLoad.Experimental.TotalRequests.ParseStop"
     units="requests">
   <owner>csharrison@chromium.org</owner>