UMA: How often are different network error screens encountered during OOBE

chrome/browser/chromeos/login/error_screens_histogram_helper.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 "chrome/browser/chromeos/login/error_screens_histogram_helper.h"
+
+#include "base/metrics/histogram.h"
+
+namespace chromeos {
+
+namespace {
+
+static const char kOobeErrorScreensCounterPrefix[] = "OOBE.NetworkErrorShown.";
+static const char kOobeTimeSpentOnErrorScreensPrefix[] =
+    "OOBE.ErrorScreensTime.";
+
+std::string ErrorToString(ErrorScreen::ErrorState error) {
+  switch (error) {
+    case ErrorScreen::ERROR_STATE_PORTAL:
+      return ".Portal";
+    case ErrorScreen::ERROR_STATE_OFFLINE:
+      return ".Offline";
+    case ErrorScreen::ERROR_STATE_PROXY:
+      return ".Proxy";
+    case ErrorScreen::ERROR_STATE_AUTH_EXT_TIMEOUT:
+      return ".AuthExtTimeout";
+    default:
+      NOTREACHED() << "Invalid ErrorState " << error;
+      return "";

[ygorshenin1, 2014/08/26 14:33:13]

nit: replace "" by std::string().

[Roman Sorokin (ftl), 2014/09/04 13:26:47]

Done.

+  }
+}
+
+}  // namespace
+
+ErrorScreensHistogramHelper::ErrorScreensHistogramHelper(
+    const char* screen_name)
+    : screen_name_(screen_name),
+      was_shown_(false),
+      last_error_shown_(ErrorScreen::ERROR_STATE_NONE) {
+}
+
+void ErrorScreensHistogramHelper::OnScreenShow() {
+  was_shown_ = true;
+}
+
+void ErrorScreensHistogramHelper::OnErrorShow(ErrorScreen::ErrorState error) {
+  OnErrorShowTime(error, base::Time::Now());
+}
+
+void ErrorScreensHistogramHelper::OnErrorShowTime(ErrorScreen::ErrorState error,
+                                                  base::Time now) {
+  last_error_shown_ = error;
+  if (error_screen_start_time.is_null())
+    error_screen_start_time = now;
+  UMA_HISTOGRAM_ENUMERATION(kOobeErrorScreensCounterPrefix + screen_name_,
+                            error,
+                            ErrorScreen::kHistogramErrorStateNum);
+}
+
+void ErrorScreensHistogramHelper::OnErrorHide() {
+  OnErrorHideTime(base::Time::Now());
+}
+
+void ErrorScreensHistogramHelper::OnErrorHideTime(base::Time now) {
+  DCHECK(!error_screen_start_time.is_null());
+  time_on_error_screens += now - error_screen_start_time;
+  error_screen_start_time = base::Time();
+}
+
+ErrorScreensHistogramHelper::~ErrorScreensHistogramHelper() {
+  if (was_shown_) {
+    if (last_error_shown_ == ErrorScreen::ERROR_STATE_NONE) {
+      UMA_HISTOGRAM_ENUMERATION(kOobeErrorScreensCounterPrefix + screen_name_,
+                                ErrorScreen::ERROR_STATE_NONE,
+                                ErrorScreen::kHistogramErrorStateNum);
+    } else {
+      if (!error_screen_start_time.is_null()) {
+        time_on_error_screens += base::Time::Now() - error_screen_start_time;
+        error_screen_start_time = base::Time();
+      }
+      UMA_HISTOGRAM_MEDIUM_TIMES(kOobeTimeSpentOnErrorScreensPrefix +

[ygorshenin1, 2014/08/26 14:33:14]

Am I right that if, for example, 30 seconds were spent on the offline error
message and after that 30 seconds were spent on the portal error message, then
60 seconds will be reported for OOBE.ErrorScreensTime.Portal?

[Roman Sorokin (ftl), 2014/09/04 13:26:47]

Yes, we decided with Nikita to report the last error screen only.
On 2014/08/26 14:33:14, ygorshenin1 wrote:

[ygorshenin1, 2014/09/04 15:13:03]

OK, could you please add an clarification to the histograms.xml as this meaning
is not-obvious?

On 2014/09/04 13:26:47, Roman Sorokin wrote:

+                                     screen_name_ +
+                                     ErrorToString(last_error_shown_),
+                                 time_on_error_screens);
+    }
+  }
+}
+
+}  // namespace chromeos