Combine boolean MediaDeviceNotifications histograms to an enumerated histogram.

chrome/browser/system_monitor/removable_device_notifications_histogram.cc

Index: chrome/browser/system_monitor/removable_device_notifications_histogram.cc
diff --git a/chrome/browser/system_monitor/removable_device_notifications_histogram.cc b/chrome/browser/system_monitor/removable_device_notifications_histogram.cc
new file mode 100644
index 0000000000000000000000000000000000000000..150df95d13a221bd92e9438d05c5cdc87623294e
--- /dev/null
+++ b/chrome/browser/system_monitor/removable_device_notifications_histogram.cc
@@ -0,0 +1,45 @@
+// Copyright (c) 2012 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 "chrome/browser/system_monitor/removable_device_notifications_histogram.h"
+
+#include "base/logging.h"
+#include "base/metrics/histogram.h"
+
+namespace chrome {
+
+namespace {
+
+// MediaDeviceNotification.DeviceInfo histogram values.
+enum DeviceInfoHistogramBuckets {
+  MASS_STORAGE_DEVICE_NAME_AND_UUID_AVAILABLE,
+  MASS_STORAGE_DEVICE_NAME_AVAILABLE_AND_UUID_NOT_AVAILABLE,

[vandebo (ex-Chrome), 2012/09/16 22:27:46]

could call this FOO_UUID_MISSING

[kmadhusu, 2012/09/17 18:29:07]

Done.

+  MASS_STORAGE_DEVICE_NAME_NOT_AVAILABLE_AND_UUID_AVAILABLE,
+  MASS_STORAGE_DEVICE_NAME_AND_UUID_NOT_AVAILABLE,
+  MTP_STORAGE_DEVICE_NAME_AND_UUID_AVAILABLE,

[vandebo (ex-Chrome), 2012/09/16 22:27:46]

the removable device notifiers only handle mass storage.  Maybe put this in
MediaStorageUtil?

[kmadhusu, 2012/09/17 18:29:07]

Moved to MediaStorageUtil.

+  MTP_STORAGE_DEVICE_NAME_AVAILABLE_AND_UUID_NOT_AVAILABLE,
+  MTP_STORAGE_DEVICE_NAME_NOT_AVAILABLE_AND_UUID_AVAILABLE,
+  MTP_STORAGE_DEVICE_NAME_AND_UUID_NOT_AVAILABLE,
+  DEVICE_INFO_BUCKET_BOUNDARY
+};
+
+}  // namespace
+
+void RecordDeviceInfoHistogram(MediaStorageUtil::Type device_type,

[vandebo (ex-Chrome), 2012/09/16 22:27:46]

bool mass_storage, so you don't have to figure out the complete type before
calling.

[kmadhusu, 2012/09/17 18:29:07]

Done.

+                               const std::string& device_uuid,
+                               const string16& device_name) {
+  int event_number = device_type == MediaStorageUtil::MTP_OR_PTP ? 4 : 0;
+  event_number += device_name.empty() ? 2 : 0;

[vandebo (ex-Chrome), 2012/09/16 22:27:46]

if (device_name.empty()) event_number += 2;

[kmadhusu, 2012/09/17 18:29:07]

Done.

+  event_number += device_uuid.empty() ? 1 : 0;
+  enum DeviceInfoHistogramBuckets event =
+      static_cast<enum DeviceInfoHistogramBuckets>(event_number);
+  if (event >= DEVICE_INFO_BUCKET_BOUNDARY) {
+    NOTREACHED();
+    return;
+  }
+  UMA_HISTOGRAM_ENUMERATION("MediaDeviceNotifications.DeviceInfo", event,
+                            DEVICE_INFO_BUCKET_BOUNDARY);
+}
+
+}  // namespace chrome