views: Mark single-argument constructors as explicit.

ui/views/controls/menu/menu_model_adapter_unittest.cc

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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 "base/utf_string_conversions.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/models/menu_model.h"
 #include "ui/base/models/menu_model_delegate.h"
 #include "ui/views/controls/menu/menu_item_view.h"
 #include "ui/views/controls/menu/menu_model_adapter.h"
 #include "ui/views/controls/menu/menu_runner.h"
 #include "ui/views/controls/menu/submenu_view.h"
 #include "ui/views/test/views_test_base.h"
 
 namespace {
 
 // Base command id for test menu and its submenu.
 const int kRootIdBase = 100;
 const int kSubmenuIdBase = 200;
 
 // Offset to return for GetFirstItemIndex().  This is an arbitrary
 // number to ensure that we aren't assuming it is 0.
 const int kFirstItemIndex = 25;
 
 class MenuModelBase : public ui::MenuModel {
  public:
-  MenuModelBase(int command_id_base) : command_id_base_(command_id_base),
-                                       last_activation_(-1) {
+  explicit MenuModelBase(int command_id_base)
+      : command_id_base_(command_id_base),
+        last_activation_(-1) {
   }
 
   virtual ~MenuModelBase() {
   }
 
   // ui::MenuModel implementation:
 
   virtual bool HasIcons() const OVERRIDE {
     return false;
   }
@@ skipping 259 matching lines @@
     submodel->set_last_activation(-1);
   }
 
   // Check that selecting the root item is safe.  The MenuModel does
   // not care about the root so MenuModelAdapter should do nothing
   // (not hit the NOTREACHED check) when the root is selected.
   static_cast<views::MenuDelegate*>(&delegate)->SelectionChanged(menu);
 }
 
 }  // namespace views