Clicking on the HaTS notification now opens the survey dialog

BUG=642078
COMPONENT=HaTS, Chrome OS

Review-Url: https://codereview.chromium.org/2294473003
Cr-Commit-Position: refs/heads/master@{#415357}

chrome/browser/chromeos/hats/hats_notification_controller.cc

@@ -180,7 +180,12 @@ std::string HatsNotificationController::id() const {
 }
 
 // message_center::NotificationDelegate override:
-void HatsNotificationController::ButtonClick(int button_index) {
+void HatsNotificationController::Click() {
+  ButtonClick(0 /* unused */);
+}
+
+// message_center::NotificationDelegate override:
+void HatsNotificationController::ButtonClick(int /* button_index */) {
   UpdateLastInteractionTime();
 
   // The dialog deletes itslef on close.

chrome/browser/chromeos/hats/hats_notification_controller.h

@@ -64,6 +64,7 @@ class HatsNotificationController : public NotificationDelegate,
   void Initialize(bool is_new_device);
   void ButtonClick(int button_index) override;
   void Close(bool by_user) override;
+  void Click() override;
   std::string id() const override;
 
   void OnImageFetched(const std::string& id, const gfx::Image& image);