Bring back the URLLoader from the old Mandoline network service.

content/network/network_context.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 "content/network/network_context.h"
+
+#include "base/command_line.h"
+#include "base/logging.h"
+#include "content/network/url_loader_impl.h"
+#include "content/public/common/content_client.h"
+#include "net/dns/host_resolver.h"
+#include "net/dns/mapped_host_resolver.h"
+#include "net/log/net_log_util.h"
+#include "net/log/write_to_file_net_log_observer.h"
+#include "net/proxy/proxy_service.h"
+#include "net/url_request/url_request_context.h"
+#include "net/url_request/url_request_context_builder.h"
+
+namespace content {
+
+namespace {
+// Logs network information to the specified file.
+const char kLogNetLog[] = "log-net-log";
+
+// Applies the specified mapping rules when resolving hosts. Please see the
+// comment of net::MappedHostResolver::AddRulesFromString() for rule format.
+const char kHostResolverRules[] = "host-resolver-rules";
+
+// Ignores certificate-related errors.
+const char kIgnoreCertificateErrors[] = "ignore-certificate-errors";
+
+std::unique_ptr<net::URLRequestContext> MakeURLRequestContext() {
+  net::URLRequestContextBuilder builder;
+  net::URLRequestContextBuilder::HttpNetworkSessionParams params;
+  const base::CommandLine* command_line =
+      base::CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(kIgnoreCertificateErrors))
+    params.ignore_certificate_errors = true;
+  builder.set_http_network_session_params(params);
+  if (command_line->HasSwitch(kHostResolverRules)) {
+    std::unique_ptr<net::HostResolver> host_resolver(
+        net::HostResolver::CreateDefaultResolver(nullptr));
+    std::unique_ptr<net::MappedHostResolver> remapped_host_resolver(
+        new net::MappedHostResolver(std::move(host_resolver)));
+    remapped_host_resolver->SetRulesFromString(
+        command_line->GetSwitchValueASCII(kHostResolverRules));
+    builder.set_host_resolver(std::move(remapped_host_resolver));
+  }
+  builder.set_accept_language("en-us,en");
+  builder.set_user_agent(GetContentClient()->GetUserAgent());
+  builder.set_proxy_service(net::ProxyService::CreateDirect());
+  net::URLRequestContextBuilder::HttpCacheParams cache_params;
+
+  // We store the cache in memory so we can run many shells in parallel when
+  // running tests, otherwise the network services in each shell will corrupt
+  // the disk cache.
+  cache_params.type = net::URLRequestContextBuilder::HttpCacheParams::IN_MEMORY;
+
+  builder.EnableHttpCache(cache_params);
+  builder.set_file_enabled(true);
+  return builder.Build();
+}
+
+}  // namespace
+
+class NetworkContext::MojoNetLog : public net::NetLog {
+ public:
+  MojoNetLog() {
+    const base::CommandLine* command_line =
+        base::CommandLine::ForCurrentProcess();
+    if (!command_line->HasSwitch(kLogNetLog))
+      return;
+    base::FilePath log_path = command_line->GetSwitchValuePath(kLogNetLog);
+    base::ScopedFILE file;
+#if defined(OS_WIN)
+    file.reset(_wfopen(log_path.value().c_str(), L"w"));
+#elif defined(OS_POSIX)
+    file.reset(fopen(log_path.value().c_str(), "w"));
+#endif
+    if (!file) {
+      LOG(ERROR) << "Could not open file " << log_path.value()
+                 << " for net logging";
+    } else {
+      write_to_file_observer_.reset(new net::WriteToFileNetLogObserver());
+      write_to_file_observer_->set_capture_mode(
+          net::NetLogCaptureMode::IncludeCookiesAndCredentials());
+      write_to_file_observer_->StartObserving(this, std::move(file), nullptr,
+                                              nullptr);
+    }
+  }
+  ~MojoNetLog() override {
+    if (write_to_file_observer_)
+      write_to_file_observer_->StopObserving(nullptr);
+  }
+
+ private:
+  std::unique_ptr<net::WriteToFileNetLogObserver> write_to_file_observer_;
+  DISALLOW_COPY_AND_ASSIGN(MojoNetLog);
+};
+
+NetworkContext::NetworkContext()
+    : net_log_(new MojoNetLog),

[yzshen1, 2017/04/11 21:58:04]

It seems this member is not used?

[jam, 2017/04/11 22:58:19]

The destructor does work

+      url_request_context_(MakeURLRequestContext()),
+      in_shutdown_(false) {}
+
+NetworkContext::~NetworkContext() {
+  in_shutdown_ = true;
+  // Call each URLLoaderImpl and ask it to release its net::URLRequest, as the
+  // corresponding net::URLRequestContext is going away with this
+  // NetworkContext. The loaders can be deregistering themselves in Cleanup(),
+  // so iterate over a copy.
+  for (auto& url_loader : url_loaders_)
+    url_loader->Cleanup();
+}
+
+void NetworkContext::RegisterURLLoader(URLLoaderImpl* url_loader) {
+  DCHECK(url_loaders_.count(url_loader) == 0);
+  url_loaders_.insert(url_loader);
+}
+
+void NetworkContext::DeregisterURLLoader(URLLoaderImpl* url_loader) {
+  if (!in_shutdown_) {
+    size_t removed_count = url_loaders_.erase(url_loader);
+    DCHECK(removed_count);
+  }
+}
+
+}  // namespace content