NoState Prefetch: nostate prefetch browser tests.

chrome/browser/prerender/prerender_manager_factory.cc

Index: chrome/browser/prerender/prerender_manager_factory.cc
diff --git a/chrome/browser/prerender/prerender_manager_factory.cc b/chrome/browser/prerender/prerender_manager_factory.cc
index 895e4f4423aeb16456b837311cf50c9027410334..630d81ef5e5c2d68519595d6f3d9f1840f976a82 100644
--- a/chrome/browser/prerender/prerender_manager_factory.cc
+++ b/chrome/browser/prerender/prerender_manager_factory.cc
@@ -21,6 +21,10 @@
 namespace prerender {
 
 // static
+PrerenderManagerFactory::PrerenderCreateFunction*
+    PrerenderManagerFactory::testing_create_function_ = nullptr;
+
+// static
 PrerenderManager* PrerenderManagerFactory::GetForBrowserContext(
     content::BrowserContext* context) {
   TRACE_EVENT0("browser", "PrerenderManagerFactory::GetForProfile")
@@ -54,6 +58,10 @@ PrerenderManagerFactory::~PrerenderManagerFactory() {
 
 KeyedService* PrerenderManagerFactory::BuildServiceInstanceFor(
     content::BrowserContext* browser_context) const {
+  if (testing_create_function_) {
+    return testing_create_function_(
+        Profile::FromBrowserContext(browser_context));
+  }
   return new PrerenderManager(Profile::FromBrowserContext(browser_context));
 }