Hook up Reader Mode InfoBar

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 441ddd975759eec65eb5b4aac562b77333853c84..04ed3d19fba5f751c3356b2710b0d25ef2d2f1b4 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -13355,6 +13355,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="DomDistiller.BarCloseButtonUsage" enum="BooleanPanelWasOpen">
+  <obsolete>
+    UI rewrite to be an InfoBar makes this metric irrelevant as of 05/2017.
+  </obsolete>
   <owner>mdjones@chromium.org</owner>
   <summary>
     Records if the close button was used before or after opening and viewing
@@ -13392,6 +13395,11 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="DomDistiller.InfoBarUsage" enum="BooleanUsage">
+  <owner>mdjones@chromium.org</owner>
+  <summary>Records if the infobar was used or closed.</summary>
+</histogram>
+
 <histogram name="DomDistiller.LongArticleScoreNMF.Negative" units="score">
   <owner>wychen@chromium.org</owner>
   <summary>
@@ -13532,6 +13540,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="DomDistiller.Time.SwipeToPaint" units="ms">

[wychen, 2017/05/16 00:19:03]

DomDistiller.Time.ViewingReaderModePanel would be obsolete after this, right?
We'd need a signal telling us how much time the user has spent in the distilled
page.

[mdjones, 2017/05/16 23:29:34]

Added the new duration metric and cleaned up a bit more.

+  <obsolete>
+    UI rewrite to be an InfoBar makes this metric irrelevant as of 05/2017.
+  </obsolete>
   <owner>wychen@chromium.org</owner>
   <summary>
     Records the time from a swipe-up gesture on ReaderModePanel to the first