Remove explicit keyword from multi-argument constructors

chrome/browser/ui/gtk/sad_tab_gtk.h

 // Copyright (c) 2011 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.
 
 #ifndef CHROME_BROWSER_UI_GTK_SAD_TAB_GTK_H_
 #define CHROME_BROWSER_UI_GTK_SAD_TAB_GTK_H_
 #pragma once
 
 typedef struct _GtkWidget GtkWidget;
 
 #include "chrome/browser/ui/gtk/owned_widget_gtk.h"
 #include "ui/base/gtk/gtk_signal.h"
 
 class TabContents;
 
 class SadTabGtk {
  public:
   enum Kind {
     CRASHED,  // The tab crashed.  Display the "Aw, Snap!" page.
     KILLED    // The tab was killed.  Display the killed tab page.
   };
 
-  explicit SadTabGtk(TabContents* tab_contents, Kind kind);
+  SadTabGtk(TabContents* tab_contents, Kind kind);
   virtual ~SadTabGtk();
 
   GtkWidget* widget() const { return event_box_.get(); }
 
  private:
   CHROMEGTK_CALLBACK_0(SadTabGtk, void, OnLinkButtonClick);
 
   void OnLinkButtonClick();
 
   TabContents* tab_contents_;
   OwnedWidgetGtk event_box_;
   Kind kind_;
 
   DISALLOW_COPY_AND_ASSIGN(SadTabGtk);
 };
 
 #endif  // CHROME_BROWSER_UI_GTK_SAD_TAB_GTK_H_