Speculatively launch Service Workers on mouse/touch events. [4/5]

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 ffbcd4f2406d7be5eb71d70e82f0147f8fd53e53..fe1e0daf7979a28a67b4ddc21b3d936cf6fea124 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -51785,6 +51785,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <summary>Execution time of ServiceWorkerGlobalScope.onmessage.</summary>
 </histogram>
 
+<histogram name="ServiceWorker.NavigationHintPrecision" enum="BooleanEnabled">
+  <owner>horo@google.com</owner>
+  <summary>
+    The precision of the speculative launch of Service Workers for navigation
+    hints. Recorded when the worker is stopped. If there was no event fetched to
+    the worker, this value is false. This means that the speculative launch was
+    meaningless.
+  </summary>
+</histogram>
+
 <histogram name="ServiceWorker.NotificationClickEvent.Time" units="ms">
   <owner>peter@chromium.org</owner>
   <summary>
@@ -100933,6 +100943,13 @@ To add a new entry, add it with any value and run test to compute valid value.
   <suffix name="3" label="Failed three times."/>
 </histogram_suffixes>
 
+<histogram_suffixes name="ServiceWorker.NavigationHint" separator=".">
+  <suffix name="LINK_MOUSE_DOWN" label="LINK_MOUSE_DOWN"/>
+  <suffix name="LINK_TAP_UNCONFIRMED" label="LINK_TAP_UNCONFIRMED"/>
+  <suffix name="LINK_TAP_DOWN" label="LINK_TAP_DOWN"/>
+  <affected-histogram name="ServiceWorker.NavigationHintPrecision"/>
+</histogram_suffixes>
+
 <histogram_suffixes name="ServiceWorker.ShutdownStatus">
   <affected-histogram name="ServiceWorker.ActivateEventStatus"/>
   <suffix name="InShutdown" label="Browser shutdown started."/>