Group ConnectToApplication-related info into a params struct.

mojo/shell/identity.cc

 // Copyright 2015 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 "mojo/shell/identity.h"
 
 #include "mojo/shell/query_util.h"
 
 namespace mojo {
 namespace shell {
 
+Identity::Identity() {}
+
 Identity::Identity(const GURL& in_url, const std::string& in_qualifier)
     : url(GetBaseURLAndQuery(in_url, nullptr)),
       qualifier(in_qualifier.empty() ? url.spec() : in_qualifier) {}
 
 // explicit
 Identity::Identity(const GURL& in_url)
     : url(GetBaseURLAndQuery(in_url, nullptr)), qualifier(url.spec()) {}
 
 bool Identity::operator<(const Identity& other) const {
   if (url != other.url)
     return url < other.url;
   return qualifier < other.qualifier;
 }
 
 }  // namespace shell
 }  // namespace mojo