Introduce SystemNetworkContextManager.

chrome/browser/net/system_network_context_manager.cc

+// Copyright 2017 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/browser/net/system_network_context_manager.h"
+
+#include "base/feature_list.h"
+#include "base/logging.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/network_service_instance.h"
+#include "content/public/common/content_features.h"
+#include "content/public/common/service_names.mojom.h"
+#include "mojo/public/cpp/bindings/associated_interface_ptr.h"
+
+namespace {
+
+content::mojom::NetworkContextParamsPtr CreateNetworkContextParams() {
+  // TODO(mmenke): Set up parameters here (No cache, in memory cookie store,
+  // etc).
+  return content::mojom::NetworkContextParams::New();
+}
+
+}  // namespace
+
+base::LazyInstance<SystemNetworkContextManager>::Leaky
+    g_system_network_context_manager = LAZY_INSTANCE_INITIALIZER;
+
+content::mojom::NetworkContext* SystemNetworkContextManager::Context() {
+  return GetInstance()->GetContext();
+}
+
+void SystemNetworkContextManager::SetUp(
+    content::mojom::NetworkContextRequest* network_context_request,
+    content::mojom::NetworkContextParamsPtr* network_context_params) {
+  if (base::FeatureList::IsEnabled(features::kNetworkService)) {
+    DCHECK(!GetInstance()->io_thread_network_context_);
+    *network_context_request =
+        mojo::MakeRequest(&GetInstance()->io_thread_network_context_);
+  } else {
+    DCHECK(!GetInstance()->system_network_context_);
+    *network_context_request =
+        mojo::MakeRequest(&GetInstance()->system_network_context_);
+  }
+  *network_context_params = CreateNetworkContextParams();
+}
+
+SystemNetworkContextManager* SystemNetworkContextManager::GetInstance() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  return g_system_network_context_manager.Pointer();
+}
+
+SystemNetworkContextManager::SystemNetworkContextManager() {}
+
+SystemNetworkContextManager::~SystemNetworkContextManager() {}
+
+content::mojom::NetworkContext* SystemNetworkContextManager::GetContext() {
+  if (!system_network_context_) {
+    // SetUp() should already have been called, and set
+    // |system_network_context_| if the network service is disabled.
+    DCHECK(base::FeatureList::IsEnabled(features::kNetworkService));
+
+    content::mojom::NetworkContextParamsPtr context_params =
+        content::mojom::NetworkContextParams::New();

[asanka, 2017/07/13 01:52:29]

did you mean to call CreateNetworkContextParams() here instead and use
|context_params| in the CreateNetworkContext() call below?

[mmenke, 2017/07/13 16:15:18]

Actually, I meant to just remove this line after I decided to inline the call,
and forgot to do that.  Inlined.

+    content::mojom::NetworkContextRequest system_network_context_request =
+        mojo::MakeRequest(&GetInstance()->system_network_context_);
+    content::GetNetworkService()->CreateNetworkContext(
+        MakeRequest(&system_network_context_), CreateNetworkContextParams());
+  }
+
+  return system_network_context_.get();
+}