Additional heuristic user interaction attribution for page load metrics

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 972a75eaf60ab01b6d4b3449704a191592e5d8c6..caa0fd45fe2556086ab7c06fc2d87dadc7bb8458 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -112104,15 +112104,47 @@ value.
   <affected-histogram name="PageLoad.AbortTiming.NewNavigation.BeforeCommit"/>
   <affected-histogram name="PageLoad.AbortTiming.Reload.BeforeCommit"/>
   <affected-histogram
-      name="PageLoad.Experimental.AbortTiming.ForwardBackNavigation.BeforeCommit"/>
+      name="PageLoad.Experimental.AbortTiming.ForwardBackNavigation.BeforeCommit">
+    <obsolete>
+      Deprecated in favor of UserGesture/UserInputEvent/BrowserInitiated.
+    </obsolete>
+  </affected-histogram>
   <affected-histogram
-      name="PageLoad.Experimental.AbortTiming.NewNavigation.BeforeCommit"/>
+      name="PageLoad.Experimental.AbortTiming.NewNavigation.BeforeCommit">
+    <obsolete>
+      Deprecated in favor of UserGesture/UserInputEvent/BrowserInitiated.
+    </obsolete>
+  </affected-histogram>
   <affected-histogram
-      name="PageLoad.Experimental.AbortTiming.Reload.BeforeCommit"/>
+      name="PageLoad.Experimental.AbortTiming.Reload.BeforeCommit">
+    <obsolete>
+      Deprecated in favor of UserGesture/UserInputEvent/BrowserInitiated.
+    </obsolete>
+  </affected-histogram>
   <affected-histogram
       name="PageLoad.PaintTiming.NavigationToFirstContentfulPaint"/>
 </histogram_suffixes>
 
+<histogram_suffixes name="PageLoadMetricsUserInitiated2" separator=".">
+  <suffix name="UserGesture"
+      label="(experimental) Page load that has a user gesture"/>
+  <suffix name="UserInputEvent"
+      label="(experimental) Page load that has a user input event"/>
+  <suffix name="BrowserInitiated"
+      label="(experimental) Page load that was initiated from the browser
+             process"/>
+  <affected-histogram
+      name="PageLoad.AbortTiming.ForwardBackNavigation.AfterCommit.BeforePaint"/>
+  <affected-histogram
+      name="PageLoad.AbortTiming.ForwardBackNavigation.BeforeCommit"/>
+  <affected-histogram
+      name="PageLoad.AbortTiming.NewNavigation.AfterCommit.BeforePaint"/>
+  <affected-histogram name="PageLoad.AbortTiming.NewNavigation.BeforeCommit"/>
+  <affected-histogram
+      name="PageLoad.AbortTiming.Reload.AfterCommit.BeforePaint"/>
+  <affected-histogram name="PageLoad.AbortTiming.Reload.BeforeCommit"/>
+</histogram_suffixes>
+
 <histogram_suffixes name="PageLoadType">
   <suffix name="HistoryLoad"
       label="but only for user pressing back or forward"/>