Add recording of visible href site engagement scores.

Add recording of AnchorElementMetrics.Visible.HrefEngagementScore2.

Bug: 850624
Change-Id: I5291067e2b9f1edfb8dd4e23fca3df802a153228
Reviewed-on: https://chromium-review.googlesource.com/1156000
Commit-Queue: Lu Chen <chelu@chromium.org>
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579594}

chrome/browser/navigation_predictor/navigation_predictor.cc

@@ -313,6 +313,9 @@ void NavigationPredictor::ReportAnchorElementMetricsOnLoad(
         engagement_service->GetScore(metric->target_url);
     DCHECK(target_engagement_score >= 0 &&
            target_engagement_score <= engagement_service->GetMaxPoints());
+    UMA_HISTOGRAM_COUNTS_100(
+        "AnchorElementMetrics.Visible.HrefEngagementScore2",
+        static_cast<int>(target_engagement_score));
 
     // Anchor elements with the same area are assigned with the same rank.
     size_t area_rank = i;

tools/metrics/histograms/histograms.xml

@@ -642,17 +642,6 @@ uploading your change for review.
   </summary>
 </histogram>
 
-<histogram name="AnchorElementMetrics.Clicked.HrefEngagementScore2"
-    units="score">
-  <owner>chelu@chromium.org</owner>
-  <owner>tbansal@chromium.org</owner>
-  <summary>
-    The site engagement score of the target link (href) of an anchor element.
-    The score is retrieved from the site engagement service. This histogram is
-    recorded when the anchor element is clicked.
-  </summary>
-</histogram>
-
 <histogram name="AnchorElementMetrics.Clicked.HrefEngagementScorePositive"
     units="score">
   <owner>chelu@chromium.org</owner>
@@ -776,7 +765,7 @@ uploading your change for review.
   </summary>
 </histogram>
 
-<histogram name="AnchorElementMetrics.ContainsImage" enum="Boolean">
+<histogram base="true" name="AnchorElementMetrics.ContainsImage" enum="Boolean">
   <owner>chelu@chromium.org</owner>
   <owner>tbansal@chromium.org</owner>
   <summary>
@@ -784,7 +773,8 @@ uploading your change for review.
   </summary>
 </histogram>
 
-<histogram name="AnchorElementMetrics.DocumentEngagementScore" units="score">
+<histogram base="true" name="AnchorElementMetrics.DocumentEngagementScore"
+    units="score">
   <owner>chelu@chromium.org</owner>
   <owner>tbansal@chromium.org</owner>
   <summary>
@@ -793,7 +783,17 @@ uploading your change for review.
   </summary>
 </histogram>
 
-<histogram name="AnchorElementMetrics.IsInIFrame" enum="Boolean">
+<histogram base="true" name="AnchorElementMetrics.HrefEngagementScore2"
+    units="score">
+  <owner>chelu@chromium.org</owner>
+  <owner>tbansal@chromium.org</owner>
+  <summary>
+    The site engagement score of the target link (href) of an anchor element.
+    The score is retrieved from the site engagement service.
+  </summary>
+</histogram>
+
+<histogram base="true" name="AnchorElementMetrics.IsInIFrame" enum="Boolean">
   <owner>chelu@chromium.org</owner>
   <owner>tbansal@chromium.org</owner>
   <summary>
@@ -801,7 +801,7 @@ uploading your change for review.
   </summary>
 </histogram>
 
-<histogram name="AnchorElementMetrics.IsSameHost" enum="Boolean">
+<histogram base="true" name="AnchorElementMetrics.IsSameHost" enum="Boolean">
   <owner>chelu@chromium.org</owner>
   <owner>tbansal@chromium.org</owner>
   <summary>
@@ -810,7 +810,8 @@ uploading your change for review.
   </summary>
 </histogram>
 
-<histogram name="AnchorElementMetrics.IsUrlIncrementedByOne" enum="Boolean">
+<histogram base="true" name="AnchorElementMetrics.IsUrlIncrementedByOne"
+    enum="Boolean">
   <owner>chelu@chromium.org</owner>
   <owner>tbansal@chromium.org</owner>
   <summary>
@@ -820,7 +821,7 @@ uploading your change for review.
   </summary>
 </histogram>
 
-<histogram name="AnchorElementMetrics.RatioArea" units="%">
+<histogram base="true" name="AnchorElementMetrics.RatioArea" units="%">
   <owner>chelu@chromium.org</owner>
   <owner>tbansal@chromium.org</owner>
   <summary>
@@ -829,8 +830,8 @@ uploading your change for review.
   </summary>
 </histogram>
 
-<histogram name="AnchorElementMetrics.RatioDistanceCenterToVisibleTop"
-    units="%">
+<histogram base="true"
+    name="AnchorElementMetrics.RatioDistanceCenterToVisibleTop" units="%">
   <owner>chelu@chromium.org</owner>
   <owner>tbansal@chromium.org</owner>
   <summary>
@@ -840,7 +841,8 @@ uploading your change for review.
   </summary>
 </histogram>
 
-<histogram name="AnchorElementMetrics.RatioDistanceRootBottom" units="%">
+<histogram base="true" name="AnchorElementMetrics.RatioDistanceRootBottom"
+    units="%">
   <owner>chelu@chromium.org</owner>
   <owner>tbansal@chromium.org</owner>
   <summary>
@@ -850,7 +852,8 @@ uploading your change for review.
   </summary>
 </histogram>
 
-<histogram name="AnchorElementMetrics.RatioDistanceRootTop" units="%">
+<histogram base="true" name="AnchorElementMetrics.RatioDistanceRootTop"
+    units="%">
   <owner>chelu@chromium.org</owner>
   <owner>tbansal@chromium.org</owner>
   <summary>
@@ -860,7 +863,8 @@ uploading your change for review.
   </summary>
 </histogram>
 
-<histogram name="AnchorElementMetrics.RatioDistanceTopToVisibleTop" units="%">
+<histogram base="true" name="AnchorElementMetrics.RatioDistanceTopToVisibleTop"
+    units="%">
   <owner>chelu@chromium.org</owner>
   <owner>tbansal@chromium.org</owner>
   <summary>
@@ -870,7 +874,7 @@ uploading your change for review.
   </summary>
 </histogram>
 
-<histogram name="AnchorElementMetrics.RatioVisibleArea" units="%">
+<histogram base="true" name="AnchorElementMetrics.RatioVisibleArea" units="%">
   <owner>chelu@chromium.org</owner>
   <owner>tbansal@chromium.org</owner>
   <summary>
@@ -116010,6 +116014,7 @@ uploading your change for review.
   <suffix name="Visible" label="Intersects with the viewport, on page load"/>
   <affected-histogram name="AnchorElementMetrics.ContainsImage"/>
   <affected-histogram name="AnchorElementMetrics.DocumentEngagementScore"/>
+  <affected-histogram name="AnchorElementMetrics.HrefEngagementScore2"/>
   <affected-histogram name="AnchorElementMetrics.IsInIFrame"/>
   <affected-histogram name="AnchorElementMetrics.IsSameHost"/>
   <affected-histogram name="AnchorElementMetrics.IsUrlIncrementedByOne"/>