Add a new app API to enable watchdog behavior restarts in kiosk apps

extensions/browser/test_extensions_browser_client.cc

Index: extensions/browser/test_extensions_browser_client.cc
diff --git a/extensions/browser/test_extensions_browser_client.cc b/extensions/browser/test_extensions_browser_client.cc
index 293d1feb1642cc6929ed0b1f3866fe439509bad3..d146b73b47c256a7032085ab1bfc7804105d876c 100644
--- a/extensions/browser/test_extensions_browser_client.cc
+++ b/extensions/browser/test_extensions_browser_client.cc
@@ -6,6 +6,7 @@
 
 #include "base/values.h"
 #include "build/build_config.h"
+#include "components/user_prefs/user_prefs.h"
 #include "content/public/browser/browser_context.h"
 #include "extensions/browser/extension_host_delegate.h"
 #include "extensions/browser/test_runtime_api_delegate.h"
@@ -24,6 +25,7 @@ TestExtensionsBrowserClient::TestExtensionsBrowserClient(
       extension_cache_(new NullExtensionCache) {
   DCHECK(main_context_);
   DCHECK(!main_context_->IsOffTheRecord());
+  user_prefs::UserPrefs::Set(main_context_, &testing_pref_service_);
 }
 
 TestExtensionsBrowserClient::~TestExtensionsBrowserClient() {}
@@ -122,7 +124,7 @@ bool TestExtensionsBrowserClient::AllowCrossRendererResourceLoad(
 
 PrefService* TestExtensionsBrowserClient::GetPrefServiceForContext(
     BrowserContext* context) {
-  return NULL;
+  return user_prefs::UserPrefs::Get(main_context_);
 }
 
 void TestExtensionsBrowserClient::GetEarlyExtensionPrefsObservers(