Use std::string instead of mojo::String in //net.

net/proxy/mojo_proxy_resolver_factory_impl.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 "net/proxy/mojo_proxy_resolver_factory_impl.h"
 
 #include <string>
 #include <utility>
 
 #include "base/macros.h"
@@ skipping 76 matching lines @@
     std::unique_ptr<ProxyResolverV8TracingFactory> proxy_resolver_factory)
     : proxy_resolver_impl_factory_(std::move(proxy_resolver_factory)) {}
 
 MojoProxyResolverFactoryImpl::MojoProxyResolverFactoryImpl()
     : MojoProxyResolverFactoryImpl(ProxyResolverV8TracingFactory::Create()) {}
 
 MojoProxyResolverFactoryImpl::~MojoProxyResolverFactoryImpl() {
 }
 
 void MojoProxyResolverFactoryImpl::CreateResolver(
-    const mojo::String& pac_script,
+    const std::string& pac_script,
     mojo::InterfaceRequest<interfaces::ProxyResolver> request,
     interfaces::ProxyResolverFactoryRequestClientPtr client) {
   // The Job will call RemoveJob on |this| when either the create request
   // finishes or |request| or |client| encounters a connection error.
-  std::unique_ptr<Job> job = base::MakeUnique<Job>(
-      this, ProxyResolverScriptData::FromUTF8(pac_script.To<std::string>()),
-      proxy_resolver_impl_factory_.get(), std::move(request),
-      std::move(client));
+  std::unique_ptr<Job> job =
+      base::MakeUnique<Job>(this, ProxyResolverScriptData::FromUTF8(pac_script),
+                            proxy_resolver_impl_factory_.get(),
+                            std::move(request), std::move(client));
   Job* job_ptr = job.get();
   jobs_[job_ptr] = std::move(job);
 }
 
 void MojoProxyResolverFactoryImpl::RemoveJob(Job* job) {
   auto it = jobs_.find(job);
   DCHECK(it != jobs_.end());
   jobs_.erase(it);
 }
 
 }  // namespace net