Add GeneratedPrefs as service dependency for SettingsPrivateEventRouter

The SettingsPrivateEventRouter is written such that it expects to be
shutdown before the GeneratedPrefs service, this CL makes this
expectation explicit by declaring a dependency in the service factory.

Bug: 1110305
Change-Id: Ica1844daa151d1f1fd161e155a313c66e066f325
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2323370Reviewed-by: dpapad <dpapad@chromium.org>
Commit-Queue: Theodore Olsauskas-Warren <sauski@google.com>
Cr-Commit-Position: refs/heads/master@{#792277}

chrome/browser/extensions/api/settings_private/settings_private_event_router_factory.cc

@@ -4,6 +4,7 @@
 
 #include "chrome/browser/extensions/api/settings_private/settings_private_event_router_factory.h"
 
+#include "chrome/browser/extensions/api/settings_private/generated_prefs_factory.h"
 #include "chrome/browser/extensions/api/settings_private/settings_private_delegate_factory.h"
 #include "chrome/browser/extensions/api/settings_private/settings_private_event_router.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
@@ -33,6 +34,7 @@ SettingsPrivateEventRouterFactory::SettingsPrivateEventRouterFactory()
           BrowserContextDependencyManager::GetInstance()) {
   DependsOn(ExtensionsBrowserClient::Get()->GetExtensionSystemFactory());
   DependsOn(EventRouterFactory::GetInstance());
+  DependsOn(settings_private::GeneratedPrefsFactory::GetInstance());
   DependsOn(SettingsPrivateDelegateFactory::GetInstance());
 }