Add method for identifying different InfoBars

components/infobars/core/infobar_container.cc

Index: components/infobars/core/infobar_container.cc
diff --git a/components/infobars/core/infobar_container.cc b/components/infobars/core/infobar_container.cc
index 90ba064d4e0b6dca083a14c0e7c0c1589c5e166d..faba7e3dd4874d99af8ae7b8b53cc7acd110e476 100644
--- a/components/infobars/core/infobar_container.cc
+++ b/components/infobars/core/infobar_container.cc
@@ -8,6 +8,9 @@
 
 #include "base/auto_reset.h"
 #include "base/logging.h"
+#include "base/metrics/histogram_base.h"
+#include "base/metrics/metrics_hashes.h"
+#include "base/metrics/sparse_histogram.h"
 #include "build/build_config.h"
 #include "components/infobars/core/infobar.h"
 #include "components/infobars/core/infobar_delegate.h"
@@ -152,6 +155,11 @@ void InfoBarContainer::AddInfoBar(InfoBar* infobar,
   PlatformSpecificAddInfoBar(infobar, position);
   infobar->set_container(this);
   infobar->Show(animate);
+
+  // Record the infobar being displayed.
+  int hashed_id = static_cast<base::HistogramBase::Sample>(

[Ilya Sherman, 2015/12/16 23:41:52]

nit: It's weird to cast to a base::HistogramBase::Sample and then store the
result in an int.  I'd pick one type and stick with it.

[Ilya Sherman, 2015/12/16 23:41:52]

nit: You might want to use one of the more explicit casts from
base/numerics/safe_conversions.h.

[gone, 2015/12/17 00:34:59]

Swapped it over to storing a Sample.  Thanks for the catch.

+      base::HashMetricName(infobar->delegate()->GetIdentifier()));
+  UMA_HISTOGRAM_SPARSE_SLOWLY("InfoBar.Added", hashed_id);
 }
 
 }  // namespace infobars