[DO NOT COMMIT] Re-use the dafsa code for s-w-r histograms

components/page_load_metrics/browser/metrics_web_contents_observer.cc

Index: components/page_load_metrics/browser/metrics_web_contents_observer.cc
diff --git a/components/page_load_metrics/browser/metrics_web_contents_observer.cc b/components/page_load_metrics/browser/metrics_web_contents_observer.cc
index 2961f1ecb5dd766e48da0cd1dc87bd6f8ba53cb7..89e94f6feb6262ef85aa111ec5aabbd64901f24e 100644
--- a/components/page_load_metrics/browser/metrics_web_contents_observer.cc
+++ b/components/page_load_metrics/browser/metrics_web_contents_observer.cc
@@ -17,6 +17,8 @@
 #include "content/public/browser/web_contents_user_data.h"
 #include "ipc/ipc_message.h"
 #include "ipc/ipc_message_macros.h"
+#include "net/base/swr_histogram_domains/swr_histogram_domains.h"
+#include "url/gurl.h"
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(
     page_load_metrics::MetricsWebContentsObserver);
@@ -64,7 +66,9 @@ base::Time WallTimeFromTimeTicks(base::TimeTicks time) {
                              base::TimeDelta::FromMinutes(10), 100)
 
 PageLoadTracker::PageLoadTracker(bool in_foreground)
-    : has_commit_(false), started_in_foreground_(in_foreground) {
+    : has_commit_(false),
+      started_in_foreground_(in_foreground),
+      include_in_stale_while_revalidate_experiment_(false) {
   RecordEvent(PAGE_LOAD_STARTED);
 }
 
@@ -89,6 +93,10 @@ void PageLoadTracker::Commit() {
   has_commit_ = true;
 }
 
+void PageLoadTracker::IncludeInStaleWhileRevalidateExperiment() {
+  include_in_stale_while_revalidate_experiment_ = true;
+}
+
 bool PageLoadTracker::UpdateTiming(const PageLoadTiming& timing) {
   // Throw away IPCs that are not relevant to the current navigation.
   if (!timing_.navigation_start.is_null() &&
@@ -134,6 +142,12 @@ void PageLoadTracker::RecordTimingHistograms() {
       PAGE_LOAD_HISTOGRAM("PageLoad.Timing2.NavigationToLoadEventFired.BG",
                           timing_.load_event_start);
     }
+    if (include_in_stale_while_revalidate_experiment_) {
+      PAGE_LOAD_HISTOGRAM(
+          "PageLoad.Timing2.NavigationToLoadEventFired_"
+          "StaleWhileRevalidateExperiment",
+          timing_.load_event_start);
+    }
   }
   if (!timing_.first_layout.is_zero()) {
     if (timing_.first_layout < background_delta) {
@@ -145,15 +159,28 @@ void PageLoadTracker::RecordTimingHistograms() {
                           timing_.first_layout);
       RecordEvent(PAGE_LOAD_SUCCESSFUL_FIRST_LAYOUT_BACKGROUND);
     }
+    if (include_in_stale_while_revalidate_experiment_) {
+      PAGE_LOAD_HISTOGRAM(
+          "PageLoad.Timing2.NavigationToFirstLayout_"
+          "StaleWhileRevalidateExperiment",
+          timing_.first_layout);
+    }
   }
   if (!timing_.first_text_paint.is_zero()) {
     if (timing_.first_text_paint < background_delta) {
       PAGE_LOAD_HISTOGRAM("PageLoad.Timing2.NavigationToFirstTextPaint",
                           timing_.first_text_paint);
+

[tyoshino (SeeGerritForStatus), 2015/10/19 07:15:10]

inserted accidentally?

[Adam Rice, 2015/10/19 12:03:07]

Yes. Fixed.

     } else {
       PAGE_LOAD_HISTOGRAM("PageLoad.Timing2.NavigationToFirstTextPaint.BG",
                           timing_.first_text_paint);
     }
+    if (include_in_stale_while_revalidate_experiment_) {
+      PAGE_LOAD_HISTOGRAM(
+          "PageLoad.Timing2.NavigationToFirstTextPaint_"
+          "StaleWhileRevalidateExperiment",
+          timing_.first_text_paint);
+    }
   }
 }
 
@@ -222,6 +249,11 @@ void MetricsWebContentsObserver::DidFinishNavigation(
   if (!IsRelevantNavigation(navigation_handle))
     return;
 
+  if (net::swr_histogram_domains::IsHostInSWRHistogramDomain(
+          navigation_handle->GetURL().host())) {
+    finished_nav->IncludeInStaleWhileRevalidateExperiment();
+  }
+
   committed_load_ = finished_nav.Pass();
   committed_load_->Commit();
 }