Remove explicit keyword from multi-argument constructors

chrome/service/cloud_print/print_system_cups.cc

 // 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.
 
 #include "chrome/service/cloud_print/print_system.h"
 
 #include <cups/cups.h>
 #include <dlfcn.h>
 #include <errno.h>
 #include <pthread.h>
@@ skipping 218 matching lines @@
 
   scoped_refptr<PrintSystemCUPS> print_system_;
   PrintSystem::PrintServerWatcher::Delegate* delegate_;
   std::string printers_hash_;
   DISALLOW_COPY_AND_ASSIGN(PrintServerWatcherCUPS);
 };
 
 class PrinterWatcherCUPS
     : public PrintSystem::PrinterWatcher {
  public:
-  explicit PrinterWatcherCUPS(PrintSystemCUPS* print_system,
-                             const std::string& printer_name)
+  PrinterWatcherCUPS(PrintSystemCUPS* print_system,
+                     const std::string& printer_name)
       : printer_name_(printer_name),
     delegate_(NULL),
     print_system_(print_system) {
   }
   ~PrinterWatcherCUPS() {
     StopWatching();
   }
 
   // PrintSystem::PrinterWatcher interface
   virtual bool StartWatching(
@@ skipping 560 matching lines @@
 void PrintSystemCUPS::RunCapsCallback(
     PrinterCapsAndDefaultsCallback* callback,
     bool succeeded,
     const std::string& printer_name,
     const printing::PrinterCapsAndDefaults& printer_info) {
   callback->Run(succeeded, printer_name, printer_info);
   delete callback;
 }
 
 }  // namespace cloud_print