Add method for identifying different InfoBars

components/infobars/core/infobar_container.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/infobars/core/infobar_container.h"
 
 #include <algorithm>
 
 #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"
 
 namespace infobars {
 
 InfoBarContainer::Delegate::~Delegate() {
 }
 
 InfoBarContainer::InfoBarContainer(Delegate* delegate)
@@ skipping 124 matching lines @@
                                   size_t position,
                                   bool animate) {
   DCHECK(std::find(infobars_.begin(), infobars_.end(), infobar) ==
       infobars_.end());
   DCHECK_LE(position, infobars_.size());
   infobars_.insert(infobars_.begin() + position, infobar);
   UpdateInfoBarArrowTargetHeights();
   PlatformSpecificAddInfoBar(infobar, position);
   infobar->set_container(this);
   infobar->Show(animate);
+
+  // Record the infobar being displayed.
+  std::string id = infobar->delegate()->GetIdentifier();
+  int hashed_id =
+      static_cast<base::HistogramBase::Sample>(base::HashMetricName(id));

[Peter Kasting, 2015/12/14 23:59:14]

Nit: Slightly shorter to just inline:

  int hashed_id = static_cast<base::HistogramBase::Sample>(
      base::HashMetricName(infobar->delegate()->GetIdentifier()));

[gone, 2015/12/15 18:36:37]

Done.

+  UMA_HISTOGRAM_SPARSE_SLOWLY("InfoBar.Added", hashed_id);
 }
 
 }  // namespace infobars