Re-check Windows proxy settings on network change.

Bug: 1054414
Change-Id: Iede646dd272413fcc8c2f9951a9ff7d663708b88
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2151887Reviewed-by: Matt Mueller <mattm@chromium.org>
Commit-Queue: Eric Roman <eroman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#760182}

net/proxy_resolution/proxy_config_service_win.cc

@@ -39,9 +39,12 @@ ProxyConfigServiceWin::ProxyConfigServiceWin(
     const NetworkTrafficAnnotationTag& traffic_annotation)
     : PollingProxyConfigService(base::TimeDelta::FromSeconds(kPollIntervalSec),
                                 &ProxyConfigServiceWin::GetCurrentProxyConfig,
-                                traffic_annotation) {}
+                                traffic_annotation) {
+  NetworkChangeNotifier::AddNetworkChangeObserver(this);
+}
 
 ProxyConfigServiceWin::~ProxyConfigServiceWin() {
+  NetworkChangeNotifier::RemoveNetworkChangeObserver(this);
   // The registry functions below will end up going to disk.  TODO: Do this on
   // another thread to avoid slowing the current thread.  http://crbug.com/61453
   base::ThreadRestrictions::ScopedAllowIO allow_io;
@@ -56,6 +59,20 @@ void ProxyConfigServiceWin::AddObserver(Observer* observer) {
   PollingProxyConfigService::AddObserver(observer);
 }
 
+void ProxyConfigServiceWin::OnNetworkChanged(
+    NetworkChangeNotifier::ConnectionType type) {
+  // Proxy settings on Windows may change when the active connection changes.
+  // For instance, after connecting to a VPN, the proxy settings for the active
+  // connection will be that for the VPN. (And ProxyConfigService only reports
+  // proxy settings for the default connection).
+
+  // This is conditioned on CONNECTION_NONE to avoid duplicating work, as
+  // NetworkChangeNotifier additionally sends it preceding completion.
+  // See https://crbug.com/1071901.
+  if (type == NetworkChangeNotifier::CONNECTION_NONE)
+    CheckForChangesNow();
+}
+
 void ProxyConfigServiceWin::StartWatchingRegistryForChanges() {
   if (!keys_to_watch_.empty())
     return;  // Already initialized.

net/proxy_resolution/proxy_config_service_win.h

@@ -15,6 +15,7 @@
 #include "base/gtest_prod_util.h"
 #include "base/strings/string16.h"
 #include "net/base/net_export.h"
+#include "net/base/network_change_notifier.h"
 #include "net/proxy_resolution/polling_proxy_config_service.h"
 #include "net/proxy_resolution/proxy_config_with_annotation.h"
 
@@ -49,7 +50,8 @@ namespace net {
 // change, or in case we got it wrong (and are not checking all possible
 // registry dependencies).
 class NET_EXPORT_PRIVATE ProxyConfigServiceWin
-    : public PollingProxyConfigService {
+    : public PollingProxyConfigService,
+      public NetworkChangeNotifier::NetworkChangeObserver {
  public:
   ProxyConfigServiceWin(const NetworkTrafficAnnotationTag& traffic_annotation);
   ~ProxyConfigServiceWin() override;
@@ -57,6 +59,9 @@ class NET_EXPORT_PRIVATE ProxyConfigServiceWin
   // Overrides a function from PollingProxyConfigService.
   void AddObserver(Observer* observer) override;
 
+  // NetworkChangeObserver implementation.
+  void OnNetworkChanged(NetworkChangeNotifier::ConnectionType type) override;
+
  private:
   FRIEND_TEST_ALL_PREFIXES(ProxyConfigServiceWinTest, SetFromIEConfig);