Add more WebAPK install metrics

chrome/browser/android/webapk/webapk_metrics.cc

Index: chrome/browser/android/webapk/webapk_metrics.cc
diff --git a/chrome/browser/android/webapk/webapk_metrics.cc b/chrome/browser/android/webapk/webapk_metrics.cc
index 82c8a107e683660481d754fa5291220be3bd1bda..fe92fb2406857fa689538c3b8178c5e30078518c 100644
--- a/chrome/browser/android/webapk/webapk_metrics.cc
+++ b/chrome/browser/android/webapk/webapk_metrics.cc
@@ -17,6 +17,10 @@ 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);
 }