Collects stats on how user interacts with the bubble.

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 eeaab506a61b8261dbfb6b575afd0e25d98a25c8..09d905ce48b426784b5fa3cc46d51a6d932f1c3d 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -26840,6 +26840,11 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="SessionCrashed.Bubble" enum="SessionCrashedBubbleUserAction">
+  <owner>yiyaoliu@chromium.org</owner>
+  <summary>How did the user interact with the SessionCrashed Bubble?</summary>
+</histogram>
+
 <histogram name="Settings.DefaultSearchProvider" enum="OmniboxSearchEngine">
   <obsolete>
     Deprecated in Chrome 30.  Use Search.DefaultSearchProviderType instead.
@@ -45756,6 +45761,16 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="2" label="Write data error"/>
 </enum>
 
+<enum name="SessionCrashedBubbleUserAction" type="int">
+  <int value="0" label="The bubble was shown"/>
+  <int value="1" label="There is error when showing the bubble."/>
+  <int value="2" label="The Restore button was clicked"/>
+  <int value="3" label="User was already optin to UMA"/>
+  <int value="4" label="User chose to optin to UMA"/>
+  <int value="5" label="User clicked on the help button"/>
+  <int value="6" label="User ignored or closed the bubble"/>
+</enum>
+
 <enum name="SessionStartupPref" type="int">
   <int value="0" label="Open home page (unused)"/>
   <int value="1" label="Continue from last opened pages"/>