Make SafeBrowsingResourceThrottleFactory::RegisterFactory() not optional.

chrome/browser/renderer_host/safe_browsing_resource_throttle_factory.cc

Index: chrome/browser/renderer_host/safe_browsing_resource_throttle_factory.cc
diff --git a/chrome/browser/renderer_host/safe_browsing_resource_throttle_factory.cc b/chrome/browser/renderer_host/safe_browsing_resource_throttle_factory.cc
index c4906c18ac21058146fbe9e6afccdbc1533908ed..7b1fe0930180d6d5919c5850ca146464e844d507 100644
--- a/chrome/browser/renderer_host/safe_browsing_resource_throttle_factory.cc
+++ b/chrome/browser/renderer_host/safe_browsing_resource_throttle_factory.cc
@@ -16,21 +16,24 @@ SafeBrowsingResourceThrottleFactory*
     SafeBrowsingResourceThrottleFactory::factory_ = NULL;
 
 // static
+void SafeBrowsingResourceThrottleFactory::RegisterFactory(
+    SafeBrowsingResourceThrottleFactory* factory) {
+  factory_ = factory;
+}
+
+// static
 ResourceThrottle* SafeBrowsingResourceThrottleFactory::Create(
     net::URLRequest* request,
     content::ResourceContext* resource_context,
     bool is_subresource,
     SafeBrowsingService* service) {
-
-#if defined(FULL_SAFE_BROWSING)
   if (factory_)
     return factory_->CreateResourceThrottle(
         request, resource_context, is_subresource, service);
+
+#if defined(FULL_SAFE_BROWSING)
   return new SafeBrowsingResourceThrottle(request, is_subresource, service);
 #elif defined(MOBILE_SAFE_BROWSING)
-  if (factory_)
-    return factory_->CreateResourceThrottle(
-        request, resource_context, is_subresource, service);
   return NULL;
 #else
 #error Need to define {FULL|MOBILE} SAFE_BROWSING mode.