[CrOS PhoneHub] Add metrics for message transfer in SecureChannel.

Add MultiDevice.SecureChannel.Nearby.MessageAction

Bug: 1106937, 1150634
Change-Id: I91bc2801c9e35b8b041b4d4c39780ed4d9f32e53
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2569117
Commit-Queue: Andre Le <leandre@chromium.org>
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#833773}

chrome/browser/chromeos/BUILD.gn

@@ -2661,6 +2661,8 @@ source_set("chromeos") {
     "secure_channel/nearby_endpoint_finder_impl.h",
     "secure_channel/secure_channel_client_provider.cc",
     "secure_channel/secure_channel_client_provider.h",
+    "secure_channel/util/histogram_util.cc",
+    "secure_channel/util/histogram_util.h",
     "service_sandbox_type.h",
     "session_length_limiter.cc",
     "session_length_limiter.h",

chrome/browser/chromeos/secure_channel/nearby_connection_broker_impl.cc

@@ -8,6 +8,7 @@
 #include "base/metrics/histogram_functions.h"
 #include "base/rand_util.h"
 #include "chrome/browser/chromeos/secure_channel/nearby_endpoint_finder.h"
+#include "chrome/browser/chromeos/secure_channel/util/histogram_util.h"
 #include "chromeos/components/multidevice/logging/logging.h"
 
 namespace chromeos {
@@ -264,6 +265,8 @@ void NearbyConnectionBrokerImpl::SendMessage(const std::string& message,
                                         BytesPayload::New(message_as_bytes))),
       base::BindOnce(&NearbyConnectionBrokerImpl::OnSendPayloadResult,
                      weak_ptr_factory_.GetWeakPtr(), std::move(callback)));
+
+  util::LogMessageAction(util::MessageAction::kMessageSent);
 }
 
 void NearbyConnectionBrokerImpl::OnConnectionInitiated(
@@ -363,6 +366,8 @@ void NearbyConnectionBrokerImpl::OnPayloadReceived(
       payload->content->get_bytes()->bytes;
   NotifyMessageReceived(
       std::string(message_as_bytes.begin(), message_as_bytes.end()));
+
+  util::LogMessageAction(util::MessageAction::kMessageReceived);
 }
 
 std::ostream& operator<<(std::ostream& stream,

chrome/browser/chromeos/secure_channel/util/histogram_util.cc

+// Copyright 2020 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/chromeos/secure_channel/util/histogram_util.h"
+
+#include "base/metrics/histogram_functions.h"
+
+namespace chromeos {
+namespace secure_channel {
+namespace util {
+
+void LogMessageAction(MessageAction message_action) {
+  base::UmaHistogramEnumeration(
+      "MultiDevice.SecureChannel.Nearby.MessageAction", message_action);
+}
+
+}  // namespace util
+}  // namespace secure_channel
+}  // namespace chromeos

chrome/browser/chromeos/secure_channel/util/histogram_util.h

+// Copyright 2020 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_SECURE_CHANNEL_UTIL_HISTOGRAM_UTIL_H_
+#define CHROME_BROWSER_CHROMEOS_SECURE_CHANNEL_UTIL_HISTOGRAM_UTIL_H_
+
+namespace chromeos {
+namespace secure_channel {
+namespace util {
+
+// Enumeration of possible message transfer action via Nearby Connection
+// library. Keep in sync with corresponding enum in
+// tools/metrics/histograms/enums.xml. These values are persisted to logs.
+// Entries should not be renumbered and numeric values should never be reused.
+enum class MessageAction {
+  kMessageSent = 0,
+  kMessageReceived = 1,
+  kMaxValue = kMessageReceived,
+};
+
+// Logs a given message transfer action.
+void LogMessageAction(MessageAction message_action);
+
+}  // namespace util
+}  // namespace secure_channel
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_SECURE_CHANNEL_UTIL_HISTOGRAM_UTIL_H_

tools/metrics/histograms/enums.xml

@@ -49789,6 +49789,11 @@ Called by update_use_counter_css.py.-->
   <int value="1" label="Completed Setup"/>
 </enum>
 
+<enum name="MultiDeviceNearbyMessageAction">
+  <int value="0" label="Message Sent"/>
+  <int value="1" label="Message Received"/>
+</enum>
+
 <enum name="MultiDeviceSetupNotification">
   <int value="0" label="New user, potential host exists"/>
   <int value="1" label="Existing user, host switched"/>

tools/metrics/histograms/histograms_xml/multi_device/histograms.xml

@@ -248,6 +248,17 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   </summary>
 </histogram>
 
+<histogram name="MultiDevice.SecureChannel.Nearby.MessageAction"
+    enum="MultiDeviceNearbyMessageAction" expires_after="2021-11-30">
+  <owner>khorimoto@chromium.org</owner>
+  <owner>better-together-dev@google.com</owner>
+  <summary>
+    Measures the completion of SecureChannel messages transfers via the Nearby
+    Connections library. Emitted when the Nearby Connections library either
+    sends or receives a message.
+  </summary>
+</histogram>
+
 <histogram name="MultiDevice.SecureChannel.Nearby.SendMessageResult"
     enum="BooleanSuccess" expires_after="2021-11-30">
   <owner>khorimoto@chromium.org</owner>