views: Mark single-argument constructors as explicit.

ui/views/controls/throbber.h

 // 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.
 
 #ifndef UI_VIEWS_CONTROLS_THROBBER_H_
 #define UI_VIEWS_CONTROLS_THROBBER_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
@@ skipping 44 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(Throbber);
 };
 
 // A SmoothedThrobber is a throbber that is representing potentially short
 // and nonoverlapping bursts of work.  SmoothedThrobber ignores small
 // pauses in the work stops and starts, and only starts its throbber after
 // a small amount of work time has passed.
 class VIEWS_EXPORT SmoothedThrobber : public Throbber {
  public:
-  SmoothedThrobber(int frame_delay_ms);
+  explicit SmoothedThrobber(int frame_delay_ms);
   SmoothedThrobber(int frame_delay_ms, SkBitmap* frames);
   virtual ~SmoothedThrobber();
 
   virtual void Start() OVERRIDE;
   virtual void Stop() OVERRIDE;
 
   void set_start_delay_ms(int value) { start_delay_ms_ = value; }
   void set_stop_delay_ms(int value) { stop_delay_ms_ = value; }
 
  private:
@@ skipping 41 matching lines @@
 
   // The checkmark image.
   const SkBitmap* checkmark_;
 
   DISALLOW_COPY_AND_ASSIGN(CheckmarkThrobber);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_THROBBER_H_