[bfcache] Track the presence of network requests for metrics

R=kinuko@chromium.org,haraken@chromium.org
BUG=933147

Change-Id: Ie6590bebb11e70e024f829045e1f8717d83e9af1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1572128
Commit-Queue: Alexander Timin <altimin@chromium.org>
Auto-Submit: Alexander Timin <altimin@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652510}

content/browser/frame_host/back_forward_cache_metrics_browsertest.cc

@@ -30,6 +30,15 @@ ukm::SourceId ToSourceId(int64_t navigation_id) {
                                 ukm::SourceIdType::NAVIGATION_ID);
 }
 
+// Some features are present in almost all page loads (especially the ones
+// which are related to the document finishing loading).
+// We ignore them to make tests easier to read and write.
+constexpr uint64_t kFeaturesToIgnoreMask =
+    1 << static_cast<size_t>(
+        blink::scheduler::WebSchedulerTrackedFeature::kDocumentLoaded) |
+    1 << static_cast<size_t>(blink::scheduler::WebSchedulerTrackedFeature::
+                                 kOutstandingNetworkRequest);
+
 using UkmMetrics = std::map<std::string, int64_t>;
 using UkmEntry = std::pair<ukm::SourceId, UkmMetrics>;
 
@@ -294,12 +303,6 @@ std::ostream& operator<<(std::ostream& os, const FeatureUsage& usage) {
 
 std::vector<FeatureUsage> GetFeatureUsageMetrics(
     ukm::TestAutoSetUkmRecorder* recorder) {
-  // Some features are present in almost all page loads (especially the ones
-  // which are related to the document finishing loading).
-  // We ignore them to make tests easier to read and write.
-  constexpr uint64_t features_to_ignore_mask =
-      ~(1 << static_cast<size_t>(
-            blink::scheduler::WebSchedulerTrackedFeature::kDocumentLoaded));
 
   std::vector<FeatureUsage> result;
   for (const auto& entry :
@@ -309,13 +312,12 @@ std::vector<FeatureUsage> GetFeatureUsageMetrics(
     FeatureUsage feature_usage;
     feature_usage.source_id = entry.first;
     feature_usage.main_frame_features =
-        entry.second.at("MainFrameFeatures") & features_to_ignore_mask;
+        entry.second.at("MainFrameFeatures") & ~kFeaturesToIgnoreMask;
     feature_usage.same_origin_subframes_features =
-        entry.second.at("SameOriginSubframesFeatures") &
-        features_to_ignore_mask;
+        entry.second.at("SameOriginSubframesFeatures") & ~kFeaturesToIgnoreMask;
     feature_usage.cross_origin_subframes_features =
         entry.second.at("CrossOriginSubframesFeatures") &
-        features_to_ignore_mask;
+        ~kFeaturesToIgnoreMask;
     result.push_back(feature_usage);
   }
   return result;
@@ -473,8 +475,9 @@ IN_PROC_BROWSER_TEST_F(BackForwardCacheMetricsBrowserTest, DedicatedWorker) {
 
   EXPECT_EQ(
       static_cast<WebContentsImpl*>(shell()->web_contents())
-          ->GetMainFrame()
-          ->scheduler_tracked_features(),
+              ->GetMainFrame()
+              ->scheduler_tracked_features() &
+          ~kFeaturesToIgnoreMask,
       1ull << static_cast<size_t>(blink::scheduler::WebSchedulerTrackedFeature::
                                       kDedicatedWorkerOrWorklet));
 }

third_party/blink/public/common/scheduler/web_scheduler_tracked_feature.h

@@ -30,8 +30,9 @@ enum class WebSchedulerTrackedFeature {
   kContainsPlugins = 12,
   kDocumentLoaded = 13,
   kDedicatedWorkerOrWorklet = 14,
+  kOutstandingNetworkRequest = 15,
 
-  kCount = 15
+  kCount = 16
 };
 
 }  // namespace scheduler

third_party/blink/renderer/core/scheduler/scheduler_affecting_features_test.cc

@@ -37,6 +37,8 @@ class SchedulingAffectingFeaturesTest : public SimTest {
              ->GetActiveFeaturesTrackedForBackForwardCacheMetrics()) {
       if (feature == SchedulingPolicy::Feature::kDocumentLoaded)
         continue;
+      if (feature == SchedulingPolicy::Feature::kOutstandingNetworkRequest)
+        continue;
       result.push_back(feature);
     }
     return result;

third_party/blink/renderer/platform/loader/fetch/resource_loader.cc

@@ -356,6 +356,12 @@ ResourceLoader::ResourceLoader(ResourceFetcher* fetcher,
   DCHECK(resource_);
   DCHECK(fetcher_);
 
+  if (FrameScheduler* frame_scheduler = fetcher->GetFrameScheduler()) {
+    feature_handle_for_scheduler_ = frame_scheduler->RegisterFeature(
+        SchedulingPolicy::Feature::kOutstandingNetworkRequest,
+        {SchedulingPolicy::RecordMetricsForBackForwardCache()});
+  }
+
   resource_->SetLoader(this);
 }
 
@@ -547,6 +553,7 @@ void ResourceLoader::Release(
   bool released = scheduler_->Release(scheduler_client_id_, option, hints);
   DCHECK(released);
   scheduler_client_id_ = ResourceLoadScheduler::kInvalidClientId;
+  feature_handle_for_scheduler_.reset();
 }
 
 void ResourceLoader::Restart(const ResourceRequest& request) {

third_party/blink/renderer/platform/loader/fetch/resource_loader.h

@@ -46,6 +46,7 @@
 #include "third_party/blink/renderer/platform/loader/fetch/resource_request.h"
 #include "third_party/blink/renderer/platform/loader/fetch/response_body_loader_client.h"
 #include "third_party/blink/renderer/platform/platform_export.h"
+#include "third_party/blink/renderer/platform/scheduler/public/frame_or_worker_scheduler.h"
 #include "third_party/blink/renderer/platform/wtf/forward.h"
 
 namespace blink {
@@ -253,6 +254,9 @@ class PLATFORM_EXPORT ResourceLoader final
   bool defers_handling_data_url_ = false;
 
   TaskRunnerTimer<ResourceLoader> cancel_timer_;
+
+  FrameScheduler::SchedulingAffectingFeatureHandle
+      feature_handle_for_scheduler_;
 };
 
 }  // namespace blink

third_party/blink/renderer/platform/scheduler/common/scheduling_policy.cc

@@ -13,6 +13,7 @@ bool SchedulingPolicy::IsFeatureSticky(SchedulingPolicy::Feature feature) {
     case Feature::kWebSocket:
     case Feature::kWebRTC:
     case Feature::kDedicatedWorkerOrWorklet:
+    case Feature::kOutstandingNetworkRequest:
       return false;
     case Feature::kMainResourceHasCacheControlNoStore:
     case Feature::kMainResourceHasCacheControlNoCache: