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

net/proxy/proxy_service.cc

 // 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 "net/proxy/proxy_service.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 198 matching lines @@
       const scoped_refptr<ProxyResolverScriptData>& /*script_data*/,
       const CompletionCallback& /*callback*/) OVERRIDE {
     return ERR_NOT_IMPLEMENTED;
   }
 };
 
 // ProxyResolver that simulates a PAC script which returns
 // |pac_string| for every single URL.
 class ProxyResolverFromPacString : public ProxyResolver {
  public:
-  ProxyResolverFromPacString(const std::string& pac_string)
+  explicit ProxyResolverFromPacString(const std::string& pac_string)
       : ProxyResolver(false /*expects_pac_bytes*/),
         pac_string_(pac_string) {}
 
   virtual int GetProxyForURL(const GURL& url,
                              ProxyInfo* results,
                              const CompletionCallback& callback,
                              RequestHandle* request,
                              const BoundNetLog& net_log) OVERRIDE {
     results->UsePacString(pac_string_);
     return OK;
@@ skipping 1331 matching lines @@
     OnCompletion(result_);
   }
 }
 
 void SyncProxyServiceHelper::OnCompletion(int rv) {
   result_ = rv;
   event_.Signal();
 }
 
 }  // namespace net