When the user selects "Share" for an offline page, share the online URL.

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 9abcaaaf6acbc5e76ac78f63feee03e994e581f2..8ff04f0221b0ee1e9e3ba79a8c9e94dbea78918b 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -31379,6 +31379,12 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="OfflinePages.SharedPageWasOffline"
+    enum="OfflinePagesSharedPageWasOffline">
+  <owner>dewittj@chromium.org</owner>
+  <summary>Whether a shared page was an offline page or not.</summary>
+</histogram>
+
 <histogram name="OfflinePages.TotalPageSize" units="MB">
   <owner>fgorski@chromium.org</owner>
   <owner>jianli@chromium.org</owner>
@@ -72865,6 +72871,11 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="7" label="Skipped"/>
 </enum>
 
+<enum name="OfflinePagesSharedPageWasOffline" type="int">
+  <int value="0" label="Online"/>
+  <int value="1" label="Offline"/>
+</enum>
+
 <enum name="OfflineStatus" type="int">
   <obsolete>
     Deprecated 4/2015.