Removes ServiceProviders from ViewManager::Embed

mojo/application/public/cpp/lazy_interface_ptr.h

 // Copyright 2014 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 MOJO_APPLICATION_PUBLIC_CPP_LAZY_INTERFACE_PTR_H_
 #define MOJO_APPLICATION_PUBLIC_CPP_LAZY_INTERFACE_PTR_H_
 
 #include "mojo/application/public/cpp/connect.h"
 #include "mojo/application/public/interfaces/service_provider.mojom.h"
 
 namespace mojo {
 
 // An InterfacePtr that will request an implementation from a specified
 // ServiceProvider when it is first accessed with the get() method.
 template <typename Interface>
 class LazyInterfacePtr : public InterfacePtr<Interface> {
  public:
   LazyInterfacePtr() : service_provider_(nullptr) {}
 
-  LazyInterfacePtr(ServiceProvider* service_provider)
+  explicit LazyInterfacePtr(ServiceProvider* service_provider)
       : service_provider_(service_provider) {}
 
   void set_service_provider(ServiceProvider* service_provider) {
     if (service_provider != service_provider_) {
       InterfacePtr<Interface>::reset();
     }
     service_provider_ = service_provider;
   }
 
   Interface* get() const {
     if (!InterfacePtr<Interface>::get() && service_provider_) {
       mojo::ConnectToService<Interface>(
           service_provider_, const_cast<LazyInterfacePtr<Interface>*>(this));
     }
     return InterfacePtr<Interface>::get();
   }
   Interface* operator->() const { return get(); }
   Interface& operator*() const { return *get(); }
 
  private:
   ServiceProvider* service_provider_;
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_APPLICATION_PUBLIC_CPP_LAZY_INTERFACE_PTR_H_