Fix use-after-free of HostResolver

Create one HostResolver per profile to avoid use-after-free in
NetworkHintsMessageFilter (5.12) or NetworkContext (5.13).

Fixes: QTBUG-75884
Change-Id: Ic1a2973b4fb0aed6bd0fa1bb9a1d7c3012c30fe0
Reviewed-by: Allan Sandfeld Jensen <[email protected]>

Author: valdmann

src/core/profile_io_data_qt.cpp

@@ -200,9 +200,11 @@ content::ResourceContext *ProfileIODataQt::resourceContext()
 void ProfileIODataQt::initializeOnIOThread()
 {
     m_networkDelegate.reset(new NetworkDelegateQt(this));
+    m_hostResolver = net::HostResolver::CreateDefaultResolver(NULL);
     m_urlRequestContext.reset(new net::URLRequestContext());
     m_urlRequestContext->set_network_delegate(m_networkDelegate.get());
     m_urlRequestContext->set_enable_brotli(base::FeatureList::IsEnabled(features::kBrotliEncoding));
+    m_urlRequestContext->set_host_resolver(m_hostResolver.get());
     // this binds factory to io thread
     m_weakPtr = m_weakPtrFactory.GetWeakPtr();
     QMutexLocker lock(&m_mutex);
@@ -289,7 +291,6 @@ void ProfileIODataQt::generateStorage()
     ct_verifier->AddLogs(ct_logs);
     m_storage->set_cert_transparency_verifier(std::move(ct_verifier));
     m_storage->set_ct_policy_enforcer(base::WrapUnique(new net::DefaultCTPolicyEnforcer()));
-    m_storage->set_host_resolver(net::HostResolver::CreateDefaultResolver(NULL));
     m_storage->set_ssl_config_service(std::make_unique<net::SSLConfigServiceDefaults>());
     if (!m_httpAuthPreferences) {
         m_httpAuthPreferences.reset(new net::HttpAuthPreferences());

src/core/profile_io_data_qt.h

@@ -120,6 +120,7 @@ class ProfileIODataQt {
     std::unique_ptr<net::HttpAuthPreferences> m_httpAuthPreferences;
     std::unique_ptr<net::URLRequestJobFactory> m_jobFactory;
     std::unique_ptr<net::TransportSecurityPersister> m_transportSecurityPersister;
+    std::unique_ptr<net::HostResolver> m_hostResolver;
     base::WeakPtr<ProfileIODataQt> m_weakPtr;
     scoped_refptr<CookieMonsterDelegateQt> m_cookieDelegate;
     content::URLRequestInterceptorScopedVector m_requestInterceptors;