Metrics for document.write script blocking

chrome/browser/page_load_metrics/observers/document_write_page_load_metrics_observer_unittest.cc

Index: chrome/browser/page_load_metrics/observers/document_write_page_load_metrics_observer_unittest.cc
diff --git a/chrome/browser/page_load_metrics/observers/document_write_page_load_metrics_observer_unittest.cc b/chrome/browser/page_load_metrics/observers/document_write_page_load_metrics_observer_unittest.cc
index 9f0a62790837f35876894e6629950178dd14b04d..0cc4c0b363bd966b6dd623ae845aade1d34beeae 100644
--- a/chrome/browser/page_load_metrics/observers/document_write_page_load_metrics_observer_unittest.cc
+++ b/chrome/browser/page_load_metrics/observers/document_write_page_load_metrics_observer_unittest.cc
@@ -16,14 +16,20 @@ class DocumentWritePageLoadMetricsObserverTest
     tracker->AddObserver(
         base::WrapUnique(new DocumentWritePageLoadMetricsObserver()));
   }
-  void AssertNoHistogramsLogged() {
+  void AssertNoPreloadHistogramsLogged() {
     histogram_tester().ExpectTotalCount(
         internal::kHistogramDocWriteParseStartToFirstContentfulPaint, 0);
   }
+
+  void AssertNoBlockHistogramsLogged() {
+    histogram_tester().ExpectTotalCount(
+        internal::kHistogramDocWriteBlockParseStartToFirstContentfulPaint, 0);
+  }
 };
 
 TEST_F(DocumentWritePageLoadMetricsObserverTest, NoMetrics) {
-  AssertNoHistogramsLogged();
+  AssertNoPreloadHistogramsLogged();
+  AssertNoBlockHistogramsLogged();
 }
 
 TEST_F(DocumentWritePageLoadMetricsObserverTest, PossiblePreload) {
@@ -61,5 +67,86 @@ TEST_F(DocumentWritePageLoadMetricsObserverTest, NoPossiblePreload) {
   SimulateTimingAndMetadataUpdate(timing, metadata);
 
   NavigateAndCommit(GURL("https://www.example.com"));
-  AssertNoHistogramsLogged();
+  AssertNoPreloadHistogramsLogged();
+}
+
+TEST_F(DocumentWritePageLoadMetricsObserverTest, PossibleBlock) {
+  base::TimeDelta contentful_paint = base::TimeDelta::FromMilliseconds(1);
+  page_load_metrics::PageLoadTiming timing;
+  timing.navigation_start = base::Time::FromDoubleT(1);
+  timing.first_contentful_paint = contentful_paint;
+  timing.parse_start = base::TimeDelta::FromMilliseconds(1);
+  PopulateRequiredTimingFields(&timing);
+
+  page_load_metrics::PageLoadMetadata metadata;
+  metadata.behavior_flags |=
+      blink::WebLoadingBehaviorFlag::WebLoadingBehaviorDocumentWriteBlock;
+  NavigateAndCommit(GURL("https://www.google.com"));
+  SimulateTimingAndMetadataUpdate(timing, metadata);
+
+  NavigateAndCommit(GURL("https://www.example.com"));
+
+  histogram_tester().ExpectTotalCount(
+      internal::kHistogramDocWriteBlockParseStartToFirstContentfulPaint, 1);
+  histogram_tester().ExpectBucketCount(
+      internal::kHistogramDocWriteBlockParseStartToFirstContentfulPaint,
+      contentful_paint.InMilliseconds(), 1);
+}
+
+TEST_F(DocumentWritePageLoadMetricsObserverTest, PossibleBlockReload) {
+  base::TimeDelta contentful_paint = base::TimeDelta::FromMilliseconds(1);
+  page_load_metrics::PageLoadTiming timing;
+  timing.navigation_start = base::Time::FromDoubleT(1);
+  timing.first_contentful_paint = contentful_paint;
+  timing.parse_start = base::TimeDelta::FromMilliseconds(1);
+  PopulateRequiredTimingFields(&timing);
+
+  page_load_metrics::PageLoadMetadata metadata;
+  metadata.behavior_flags |=
+      blink::WebLoadingBehaviorFlag::WebLoadingBehaviorDocumentWriteBlockReload;
+  NavigateAndCommit(GURL("https://www.google.com"));
+  SimulateTimingAndMetadataUpdate(timing, metadata);
+
+  NavigateAndCommit(GURL("https://www.example.com"));
+
+  histogram_tester().ExpectTotalCount(
+      internal::kHistogramDocWriteBlockReloadCount, 1);
+
+  // Another reload.
+  NavigateAndCommit(GURL("https://www.google.com"));
+  SimulateTimingAndMetadataUpdate(timing, metadata);
+  NavigateAndCommit(GURL("https://www.example.com"));
+
+  histogram_tester().ExpectTotalCount(
+      internal::kHistogramDocWriteBlockReloadCount, 2);
+}
+
+TEST_F(DocumentWritePageLoadMetricsObserverTest, NoPossibleBlock) {
+  base::TimeDelta contentful_paint = base::TimeDelta::FromMilliseconds(1);
+  page_load_metrics::PageLoadTiming timing;
+  timing.navigation_start = base::Time::FromDoubleT(1);
+  timing.first_contentful_paint = contentful_paint;
+  PopulateRequiredTimingFields(&timing);
+
+  page_load_metrics::PageLoadMetadata metadata;
+  NavigateAndCommit(GURL("https://www.google.com"));
+  SimulateTimingAndMetadataUpdate(timing, metadata);
+
+  NavigateAndCommit(GURL("https://www.example.com"));
+  AssertNoBlockHistogramsLogged();
+}
+
+TEST_F(DocumentWritePageLoadMetricsObserverTest, ValidFeatureFlags) {

[Charlie Harrison, 2016/05/02 21:48:28]

This test does not belong here. Probably it belongs in blink/platform. It is not
really that necessary though. This kind of mistake will usually be caught in
code review / other tests. Up to you.

[shivanisha, 2016/05/03 18:42:03]

Agree its not really needed. Also might not be practically maintainable as any
new value will need to be added here. Removing the test. Also removing the
comment from the definition of WebLoadingBehaviorFlag.

+  // Add any new flag added to blink::WebLoadingBehaviorFlag here
+  // to test no two values are unintentionally created equal, by
+  // say, a merging error.
+  std::vector<int> flags{blink::WebLoadingBehaviorDocumentWriteEvaluator,
+                         blink::WebLoadingBehaviorServiceWorkerControlled,
+                         blink::WebLoadingBehaviorDocumentWriteBlock,
+                         blink::WebLoadingBehaviorDocumentWriteBlockReload};
+
+  std::unordered_set<int> flags_set;
+  for (int flag : flags) {
+    EXPECT_TRUE(flags_set.insert(flag).second);
+  }
 }