Added UMA Metrics for SMS UI in the status area.

ash/common/system/chromeos/network/tray_sms.cc

Index: ash/common/system/chromeos/network/tray_sms.cc
diff --git a/ash/common/system/chromeos/network/tray_sms.cc b/ash/common/system/chromeos/network/tray_sms.cc
index 45781d3f1fdedb31c44c4d560e95dc031e9a56b4..24194b5feac0707053d32259ef8022aef08e591f 100644
--- a/ash/common/system/chromeos/network/tray_sms.cc
+++ b/ash/common/system/chromeos/network/tray_sms.cc
@@ -5,6 +5,7 @@
 #include "ash/common/system/chromeos/network/tray_sms.h"
 
 #include "ash/common/material_design/material_design_controller.h"
+#include "ash/common/metrics/user_metrics_action.h"
 #include "ash/common/system/tray/fixed_sized_scroll_view.h"
 #include "ash/common/system/tray/system_tray_bubble.h"
 #include "ash/common/system/tray/tray_constants.h"
@@ -13,6 +14,7 @@
 #include "ash/common/system/tray/tray_item_view.h"
 #include "ash/common/system/tray/tray_notification_view.h"
 #include "ash/common/system/tray/view_click_listener.h"
+#include "ash/common/wm_shell.h"
 #include "ash/system/tray/system_tray.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
@@ -123,7 +125,10 @@ class TraySms::SmsMessageView : public views::View,
 
   // Overridden from ButtonListener.
   void ButtonPressed(views::Button* sender, const ui::Event& event) override {
-    owner_->RemoveMessage(index_);
+    if (owner_->RemoveMessage(index_)) {
+      WmShell::Get()->RecordUserMetricsAction(
+          UMA_STATUS_AREA_SMS_DISMISS_MSG_DETAILED_VIEW);
+    }
     owner_->Update(false);
   }
 
@@ -271,7 +276,12 @@ class TraySms::SmsNotificationView : public TrayNotificationView {
   }
 
   // Overridden from TrayNotificationView:
-  void OnClose() override { tray_sms()->RemoveMessage(message_index_); }
+  void OnClose() override {
+    if (tray_sms()->RemoveMessage(message_index_)) {
+      WmShell::Get()->RecordUserMetricsAction(
+          UMA_STATUS_AREA_SMS_DISMISS_MSG_NOTIFICATION_VIEW);
+    }
+  }
 
   void OnClickAction() override { owner()->PopupDetailedView(0, true); }
 
@@ -315,6 +325,7 @@ views::View* TraySms::CreateDetailedView(LoginStatus status) {
   if (messages_.empty())
     return NULL;
   detailed_ = new SmsDetailedView(this);
+  WmShell::Get()->RecordUserMetricsAction(UMA_STATUS_AREA_DETAILED_SMS_VIEW);
   return detailed_;
 }
 
@@ -388,9 +399,11 @@ bool TraySms::GetLatestMessage(size_t* index,
   return true;
 }
 
-void TraySms::RemoveMessage(size_t index) {
-  if (index < messages_.GetSize())
-    messages_.Remove(index, NULL);
+bool TraySms::RemoveMessage(size_t index) {
+  if (index >= messages_.GetSize())
+    return false;
+  messages_.Remove(index, NULL);

[stevenjb, 2016/07/07 17:54:36]

NULL -> nullptr throughout the file

[bruthig, 2016/07/07 18:01:38]

Done.

+  return true;
 }
 
 void TraySms::Update(bool notify) {