Export a private webstore API to call into the new inline sign-in flow.

components/keyed_service/content/refcounted_browser_context_keyed_service_factory.cc

Index: components/keyed_service/content/refcounted_browser_context_keyed_service_factory.cc
diff --git a/components/keyed_service/content/refcounted_browser_context_keyed_service_factory.cc b/components/keyed_service/content/refcounted_browser_context_keyed_service_factory.cc
index 4f75d99a72e6dbbb1504f04d7e0c9622f5a6b01e..6876ce5c5f0e31a9a8b7251150b86b89cf37db1d 100644
--- a/components/keyed_service/content/refcounted_browser_context_keyed_service_factory.cc
+++ b/components/keyed_service/content/refcounted_browser_context_keyed_service_factory.cc
@@ -13,6 +13,11 @@
 void RefcountedBrowserContextKeyedServiceFactory::SetTestingFactory(
     content::BrowserContext* context,
     TestingFactoryFunction testing_factory) {
+  if (!context) {
+    testing_factories_[NULL] = testing_factory;
+    return;
+  }
+
   // Destroying the context may cause us to lose data about whether |context|
   // has our preferences registered on it (since the context object itself
   // isn't dead). See if we need to readd it once we've gone through normal
@@ -71,10 +76,12 @@ RefcountedBrowserContextKeyedServiceFactory::GetServiceForBrowserContext(
 
   // Create new object.
   // Check to see if we have a per-BrowserContext testing factory that we should
-  // use instead of default behavior.
+  // use instead of default behavior. Check for a global factory as well.
   scoped_refptr<RefcountedBrowserContextKeyedService> service;
   BrowserContextOverriddenTestingFunctions::const_iterator jt =
       testing_factories_.find(context);
+  if (jt == testing_factories_.end())
+    jt = testing_factories_.find(NULL);
   if (jt != testing_factories_.end()) {
     if (jt->second) {
       if (!context->IsOffTheRecord())