Add more WebAPK install metrics

chrome/browser/android/webapk/webapk_metrics.cc

 // Copyright 2016 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/android/webapk/webapk_metrics.h"
 
 #include "base/metrics/histogram_macros.h"
 #include "base/time/time.h"
 #include "chrome/browser/android/webapk/chrome_webapk_host.h"
 
 namespace webapk {
 
 const char kGooglePlayInstallState[] = "WebApk.Install.GooglePlayInstallState";
 const char kInstallDurationHistogram[] = "WebApk.Install.InstallDuration";
 const char kInstallEventHistogram[] = "WebApk.Install.InstallEvent";
 const char kInstallSourceHistogram[] = "WebApk.Install.InstallSource";
 const char kInfoBarShownHistogram[] = "WebApk.Install.InfoBarShown";
 const char kUserActionHistogram[] = "WebApk.Install.UserAction";
 
+void TrackRequestTokenDuration(base::TimeDelta delta) {
+  UMA_HISTOGRAM_TIMES("WebApk.Install.RequestTokenDuration", delta);
+}
+
 void TrackInstallDuration(base::TimeDelta delta) {
   UMA_HISTOGRAM_MEDIUM_TIMES(kInstallDurationHistogram, delta);
 }
 
 void TrackInstallEvent(InstallEvent event) {
   UMA_HISTOGRAM_ENUMERATION(kInstallEventHistogram, event, INSTALL_EVENT_MAX);
 }
 
 void TrackInstallSource(InstallSource event) {
   UMA_HISTOGRAM_ENUMERATION(kInstallSourceHistogram, event, INSTALL_SOURCE_MAX);
 }
 
 void TrackInstallInfoBarShown(InfoBarShown event) {
   UMA_HISTOGRAM_ENUMERATION(kInfoBarShownHistogram, event,
                             WEBAPK_INFOBAR_SHOWN_MAX);
 }
 
 void TrackUserAction(UserAction event) {
   UMA_HISTOGRAM_ENUMERATION(kUserActionHistogram, event, USER_ACTION_MAX);
 }
 
 void TrackGooglePlayInstallState(GooglePlayInstallState state) {
   UMA_HISTOGRAM_ENUMERATION(kGooglePlayInstallState, static_cast<int>(state),
                             static_cast<int>(GooglePlayInstallState::MAX));
 }
 
 }  // namespace webapk