Respect QuicAllowed policy for new streams

chrome/browser/net/net_pref_observer.cc

Index: chrome/browser/net/net_pref_observer.cc
diff --git a/chrome/browser/net/net_pref_observer.cc b/chrome/browser/net/net_pref_observer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..7e92befd32dd51ce3fe4c4d8f4f26e8837379490
--- /dev/null
+++ b/chrome/browser/net/net_pref_observer.cc
@@ -0,0 +1,89 @@
+// Copyright (c) 2012 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/net_pref_observer.h"
+
+#include "base/bind.h"
+#include "base/command_line.h"
+#include "base/logging.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/io_thread.h"
+#include "chrome/browser/profiles/profile_manager.h"
+#include "chrome/browser/safe_browsing/safe_browsing_service.h"
+#include "chrome/common/chrome_switches.h"
+#include "chrome/common/pref_names.h"
+#include "components/pref_registry/pref_registry_syncable.h"
+#include "components/prefs/pref_service.h"
+#include "content/public/browser/browser_thread.h"
+
+#include "net/http/http_network_session.h"
+
+using content::BrowserThread;
+
+NetPrefObserver::NetPrefObserver(
+    PrefService* prefs,
+    UpdateNetParamsCallback update_net_params_callback)
+    : update_net_params_callback_(update_net_params_callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(prefs);
+
+  base::Closure prefs_callback =
+      base::Bind(&NetPrefObserver::ApplySettings, base::Unretained(this));
+  quic_allowed_.Init(prefs::kQuicAllowed, prefs, prefs_callback);
+
+  ApplySettings();
+}
+
+NetPrefObserver::~NetPrefObserver() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+}
+
+void NetPrefObserver::ApplySettings() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  IOThread* io_thread = g_browser_process->io_thread();
+  if (!io_thread)
+    return;
+
+  bool quic_allowed_by_policy = true;
+  if (quic_allowed_.IsManaged()) {
+    quic_allowed_by_policy = *quic_allowed_;
+  }
+
+  // If QUIC has already been disabled, don't re-enable it. Currently,
+  // re-enabling QUIC requires a restart. If we want to support re-enabling QUIC
+  // dynamically, we'd have to enable it only if all active profiles allow QUIC.
+  // We'd also need to evaluate command-line switches::kDisableQuic here.
+  if (quic_allowed_by_policy)
+    return;
+
+  NetParamsChange net_params_change;
+  net_params_change.quic_enabled_new = false;
+  update_net_params_callback_.Run(net_params_change);
+
+  // Apply settings for globally owned HttpNetworkSessions

[Bence, 2016/12/26 18:47:56]

Please end this sentence with a period.

[pmarko, 2017/01/02 10:33:55]

Done.

+  if (g_browser_process->safe_browsing_service()) {
+    g_browser_process->safe_browsing_service()->UpdateNetParams(
+        net_params_change);
+  }
+
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&NetPrefObserver::ApplySettingsOnIOThread,
+                 base::Unretained(this), io_thread, net_params_change));
+}
+
+void NetPrefObserver::ApplySettingsOnIOThread(
+    IOThread* io_thread,
+    NetParamsChange net_params_change) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  io_thread->UpdateNetworkSessionParams(net_params_change.quic_enabled_new);
+}
+
+// static
+void NetPrefObserver::RegisterProfilePrefs(
+    user_prefs::PrefRegistrySyncable* registry) {
+  registry->RegisterBooleanPref(prefs::kQuicAllowed, true);
+}