Cleanup: Fix some lint errors in chrome/browser/ui.

chrome/browser/ui/ash/multi_user/multi_user_warning_dialog.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/ash/multi_user/multi_user_warning_dialog.h"
 
 #include "ash/shell.h"
 #include "grit/generated_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
@@ skipping 13 matching lines @@
 
 const int kPaddingToMessage = 30;
 const int kPaddingToCheckBox = 50;
 const int kInset = 40;
 const int kTopInset = 10;
 
 ////////////////////////////////////////////////////////////////////////////////
 // Dialog for multi-profiles teleport warning.
 class TeleportWarningView : public views::DialogDelegateView {
  public:
-  TeleportWarningView(base::Callback<void(bool)> on_accept);
+  explicit TeleportWarningView(const base::Callback<void(bool)>& on_accept);
   virtual ~TeleportWarningView();
 
-  static void ShowDialog(const base::Callback<void(bool)> on_accept);
+  static void ShowDialog(const base::Callback<void(bool)>& on_accept);
 
   // views::DialogDelegate overrides.
   virtual bool Accept() OVERRIDE;
 
   // views::WidgetDelegate overrides.
   virtual ui::ModalType GetModalType() const OVERRIDE;
 
   // views::View overrides.
   virtual gfx::Size GetPreferredSize() const OVERRIDE;
 
  private:
   void InitDialog();
 
   scoped_ptr<views::Checkbox> no_show_checkbox_;
   const base::Callback<void(bool)> on_accept_;
 
   DISALLOW_COPY_AND_ASSIGN(TeleportWarningView);
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 // TeleportWarningView implementation.
 
 TeleportWarningView::TeleportWarningView(
-    const base::Callback<void(bool)> on_accept)
+    const base::Callback<void(bool)>& on_accept)
     : on_accept_(on_accept) {
 }
 
 TeleportWarningView::~TeleportWarningView() {
 }
 
 // static
 void TeleportWarningView::ShowDialog(
-    const base::Callback<void(bool)> on_accept) {
+    const base::Callback<void(bool)>& on_accept) {
   TeleportWarningView* dialog_view =
       new TeleportWarningView(on_accept);
   views::DialogDelegate::CreateDialogWidget(
       dialog_view, ash::Shell::GetTargetRootWindow(), NULL);
   dialog_view->InitDialog();
   views::Widget* widget = dialog_view->GetWidget();
   DCHECK(widget);
   widget->Show();
 }
 
@@ skipping 68 matching lines @@
   SetLayoutManager(grid_layout);
   Layout();
 }
 
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // Factory function.
 
 void ShowMultiprofilesWarningDialog(
-   const base::Callback<void(bool)> on_accept) {
+    const base::Callback<void(bool)>& on_accept) {
   TeleportWarningView::ShowDialog(on_accept);
 }
 
 }  // namespace chromeos