Fix a11y text of enterprise managed button.

Browser test requires all focusable views to have appropriate a11y
texts. For EnterpriseManagedView, we manually override tooltip text,
but it was not properly configured as a11y data. We can fix this by
just using Button's SetTooltipText.

TEST=SystemTrayClientEnterpriseTest.TrayEnterprise
(--enable-features=SystemTrayUnified)
BUG=847104

Change-Id: I8eb0e051446e4fcff4be691bf42e7af9fe99b8dd
Reviewed-on: https://chromium-review.googlesource.com/1088328Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Tetsui Ohkubo <tetsui@chromium.org>
Cr-Commit-Position: refs/heads/master@{#564909}

ash/system/unified/unified_system_info_view.cc

@@ -238,10 +238,6 @@ class EnterpriseManagedView : public ManagedStateView,
   // EnterpriseDomainObserver:
   void OnEnterpriseDomainChanged() override;
 
-  // views::View:
-  bool GetTooltipText(const gfx::Point& p,
-                      base::string16* tooltip) const override;
-
  private:
   void Update();
 
@@ -262,23 +258,6 @@ EnterpriseManagedView::~EnterpriseManagedView() {
   Shell::Get()->system_tray_model()->enterprise_domain()->RemoveObserver(this);
 }
 
-bool EnterpriseManagedView::GetTooltipText(const gfx::Point& p,
-                                           base::string16* tooltip) const {
-  EnterpriseDomainModel* model =
-      Shell::Get()->system_tray_model()->enterprise_domain();
-  if (model->active_directory_managed()) {
-    *tooltip = l10n_util::GetStringUTF16(IDS_ASH_ENTERPRISE_DEVICE_MANAGED);
-    return true;
-  } else if (!model->enterprise_display_domain().empty()) {
-    *tooltip = l10n_util::GetStringFUTF16(
-        IDS_ASH_ENTERPRISE_DEVICE_MANAGED_BY,
-        base::UTF8ToUTF16(model->enterprise_display_domain()));
-    return true;
-  } else {
-    return false;
-  }
-}
-
 void EnterpriseManagedView::ButtonPressed(views::Button* sender,
                                           const ui::Event& event) {
   Shell::Get()->system_tray_controller()->ShowEnterpriseInfo();
@@ -293,6 +272,15 @@ void EnterpriseManagedView::Update() {
       Shell::Get()->system_tray_model()->enterprise_domain();
   SetVisible(model->active_directory_managed() ||
              !model->enterprise_display_domain().empty());
+
+  if (model->active_directory_managed()) {
+    SetTooltipText(
+        l10n_util::GetStringUTF16(IDS_ASH_ENTERPRISE_DEVICE_MANAGED));
+  } else if (!model->enterprise_display_domain().empty()) {
+    SetTooltipText(l10n_util::GetStringFUTF16(
+        IDS_ASH_ENTERPRISE_DEVICE_MANAGED_BY,
+        base::UTF8ToUTF16(model->enterprise_display_domain())));
+  }
 }
 
 // A view that shows whether the user is supervised or a child.
@@ -301,10 +289,6 @@ class SupervisedUserView : public ManagedStateView {
   SupervisedUserView();
   ~SupervisedUserView() override = default;
 
-  // views::View:
-  bool GetTooltipText(const gfx::Point& p,
-                      base::string16* tooltip) const override;
-
  private:
   DISALLOW_COPY_AND_ASSIGN(SupervisedUserView);
 };
@@ -314,14 +298,8 @@ SupervisedUserView::SupervisedUserView()
                        IDS_ASH_STATUS_TRAY_SUPERVISED_LABEL,
                        GetSupervisedUserIcon()) {
   SetVisible(Shell::Get()->session_controller()->IsUserSupervised());
-}
-
-bool SupervisedUserView::GetTooltipText(const gfx::Point& p,
-                                        base::string16* tooltip) const {
   if (Shell::Get()->session_controller()->IsUserSupervised())
-    return false;
-  *tooltip = GetSupervisedUserMessage();
-  return true;
+    SetTooltipText(GetSupervisedUserMessage());
 }
 
 }  // namespace