Add method for identifying different InfoBars

components/infobars/core/infobar_delegate.h

Index: components/infobars/core/infobar_delegate.h
diff --git a/components/infobars/core/infobar_delegate.h b/components/infobars/core/infobar_delegate.h
index bed797f461274d2990cb5e3fe4679f14cd21b819..6f62ab1550c566fdf44cd8e265680d81dbc1a85f 100644
--- a/components/infobars/core/infobar_delegate.h
+++ b/components/infobars/core/infobar_delegate.h
@@ -83,6 +83,12 @@ class InfoBarDelegate {
   // as background color) of the infobar.
   virtual Type GetInfoBarType() const;
 
+  // Returns a unique string identifying the infobar.
+  // Implementers must update the InfoBarType enum in histograms.xml with the
+  // string provided by this function as the key and
+  // base::HashMetricName(string) as its value.
+  virtual std::string GetIdentifier() const = 0;
+
   virtual InfoBarAutomationType GetInfoBarAutomationType() const;
 
   // Returns the resource ID of the icon to be shown for this InfoBar.  If the