Add missing (and remove superfluous) 'explicit' from constructors.

chrome/browser/ui/cocoa/about_ipc_dialog.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_COCOA_ABOUT_IPC_DIALOG_H_
 #define CHROME_BROWSER_UI_COCOA_ABOUT_IPC_DIALOG_H_
 
 #include "ipc/ipc_logging.h"
 #include "ipc/ipc_message_utils.h"
 
 #if defined(IPC_MESSAGE_LOG_ENABLED)
 
 #ifdef __OBJC__
 @class AboutIPCController;
 #else
 class AboutIPCController;
 #endif
 
 
 // On Windows, the AboutIPCDialog is a views::View.  On Mac we have a
 // Cocoa dialog.  This class bridges from C++ to ObjC.
 class AboutIPCBridge : public IPC::Logging::Consumer {
  public:
-  AboutIPCBridge(AboutIPCController* controller) : controller_(controller) { }
+  explicit AboutIPCBridge(AboutIPCController* controller)
+      : controller_(controller) { }
   virtual ~AboutIPCBridge() { }
 
   // IPC::Logging::Consumer implementation.
   virtual void Log(const IPC::LogData& data) OVERRIDE;
 
  private:
   AboutIPCController* controller_;  // weak; owns me
   DISALLOW_COPY_AND_ASSIGN(AboutIPCBridge);
 };
 
 #endif  // IPC_MESSAGE_LOG_ENABLED
 
 #endif  // CHROME_BROWSER_UI_COCOA_ABOUT_IPC_DIALOG_H_