Respect QuicAllowed policy for new streams

chrome/browser/profiles/profile_impl.cc

Index: chrome/browser/profiles/profile_impl.cc
diff --git a/chrome/browser/profiles/profile_impl.cc b/chrome/browser/profiles/profile_impl.cc
index 9c4752f9e99322b3d7c62c50f15fe83525a7a52e..9136fdabfff5afbd247e8d0592f4fdb73a203d6d 100644
--- a/chrome/browser/profiles/profile_impl.cc
+++ b/chrome/browser/profiles/profile_impl.cc
@@ -44,6 +44,7 @@
 #include "chrome/browser/download/chrome_download_manager_delegate.h"
 #include "chrome/browser/download/download_service.h"
 #include "chrome/browser/download/download_service_factory.h"
+#include "chrome/browser/net/net_pref_observer.h"
 #include "chrome/browser/net/predictor.h"
 #include "chrome/browser/net/proxy_service_factory.h"
 #include "chrome/browser/permissions/permission_manager.h"
@@ -115,6 +116,7 @@
 #include "content/public/common/content_constants.h"
 #include "content/public/common/page_zoom.h"
 #include "extensions/features/features.h"
+#include "net/http/http_network_session.h"
 #include "ppapi/features/features.h"
 #include "printing/features/features.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -622,6 +624,12 @@ void ProfileImpl::DoFinalInit() {
                 session_cookie_mode, GetSpecialStoragePolicy(),
                 CreateDomainReliabilityMonitor(local_state));
 
+  DCHECK(!net_pref_observer_);
+  NetPrefObserver::UpdateNetParamsCallback update_net_params_callback =
+      base::Bind(&ProfileImpl::UpdateNetParams, base::Unretained(this));
+  net_pref_observer_ = base::MakeUnique<NetPrefObserver>(
+      prefs_.get(), update_net_params_callback);
+
 #if BUILDFLAG(ENABLE_PLUGINS)
   ChromePluginServiceFilter::GetInstance()->RegisterResourceContext(
       this, io_data_.GetResourceContextNoInit());
@@ -1282,3 +1290,8 @@ ProfileImpl::CreateDomainReliabilityMonitor(PrefService* local_state) {
   return service->CreateMonitor(
       BrowserThread::GetTaskRunnerForThread(BrowserThread::IO));
 }
+
+void ProfileImpl::UpdateNetParams(
+    NetPrefObserver::NetParamsChange net_params_change) {
+  io_data_.UpdateNetParams(net_params_change);

[mmenke, 2017/01/03 18:49:40]

BUG:  There are potentially multiple profiles.  IOData shouldn't just follow the
parameters of the one which had its QUIC status most recently changed.  Not sure
how group policy is normally applied to global objects.

[pmarko, 2017/01/03 19:30:49]

As far as I can see, this is not actually global - every Profile(Impl) has its
own io_data_ - it's an instance of a ProfileIOData subclass (here,
ProfileImplIOData) owned by the profile. Or am I missing something here?

But yes, there are global HttpNetworkSessions owned by io_thread /
g_browser_process->safe_browsing_service() , these are updated directly from
NetPrefObserver, so your concern does indeed apply to these.

That's why NetPrefObserver only propagates changes true->false, see
net_pref_observer.cc:58. This way, changes false->true require a restart, but
that's OK with the customer needing this so it might be a good compromise. If we
didn't do that, we'd have to keep a look at all profiles, && their quicallowed
all together and pass that to the globally-owned HttpNetworkSessions, or
something like that.

[mmenke, 2017/01/03 19:35:42]

Oops, sorry, was thinking this was IOData...Where is IOData's corresponding
method called?

+}