content: convert user action notification to observer usage

chrome/browser/metrics/metrics_service.cc

Index: chrome/browser/metrics/metrics_service.cc
diff --git a/chrome/browser/metrics/metrics_service.cc b/chrome/browser/metrics/metrics_service.cc
index 303adb046ffbb9b456dcba173b343c25d46a6ba3..ab520e4624eeffb6297ed08915486b1fdde938d3 100644
--- a/chrome/browser/metrics/metrics_service.cc
+++ b/chrome/browser/metrics/metrics_service.cc
@@ -668,8 +668,6 @@ void MetricsService::SetUpNotifications(
                  content::NotificationService::AllBrowserContextsAndSources());
   registrar->Add(observer, chrome::NOTIFICATION_BROWSER_CLOSED,
                  content::NotificationService::AllSources());
-  registrar->Add(observer, content::NOTIFICATION_USER_ACTION,
-                 content::NotificationService::AllSources());
   registrar->Add(observer, chrome::NOTIFICATION_TAB_PARENTED,
                  content::NotificationService::AllSources());
   registrar->Add(observer, chrome::NOTIFICATION_TAB_CLOSING,
@@ -702,15 +700,10 @@ void MetricsService::Observe(int type,
   DCHECK(log_manager_.current_log());
   DCHECK(IsSingleThreaded());
 
-  if (!CanLogNotification(type, source, details))
+  if (!CanLogNotification())
     return;
 
   switch (type) {
-    case content::NOTIFICATION_USER_ACTION:
-         log_manager_.current_log()->RecordUserAction(
-             *content::Details<const char*>(details).ptr());
-      break;
-
     case chrome::NOTIFICATION_BROWSER_OPENED:
     case chrome::NOTIFICATION_BROWSER_CLOSED: {
       Browser* browser = content::Source<Browser>(source).ptr();
@@ -791,6 +784,14 @@ void MetricsService::Observe(int type,
   HandleIdleSinceLastTransmission(false);
 }
 
+void MetricsService::UserAction(const std::string& action) {
+  if (!CanLogNotification())
+    return;
+
+  log_manager_.current_log()->RecordUserAction(action.c_str());
+  HandleIdleSinceLastTransmission(false);
+}
+
 void MetricsService::HandleIdleSinceLastTransmission(bool in_idle) {
   // If there wasn't a lot of action, maybe the computer was asleep, in which
   // case, the log transmissions should have stopped.  Here we start them up
@@ -1945,10 +1946,7 @@ void MetricsService::RecordPluginChanges(PrefService* pref) {
   child_process_stats_buffer_.clear();
 }
 
-bool MetricsService::CanLogNotification(
-    int type,
-    const content::NotificationSource& source,
-    const content::NotificationDetails& details) {
+bool MetricsService::CanLogNotification() {
   // We simply don't log anything to UMA if there is a single incognito
   // session visible. The problem is that we always notify using the orginal
   // profile in order to simplify notification processing.