Introduce a field trial for Instant.

chrome/browser/autocomplete/search_provider_unittest.cc

Index: chrome/browser/autocomplete/search_provider_unittest.cc
diff --git a/chrome/browser/autocomplete/search_provider_unittest.cc b/chrome/browser/autocomplete/search_provider_unittest.cc
index 99b07e0355dcdd852bea1dfe1cfd1d665678d6c8..2f5a3a98125b8f8e52ed24f9f22f6fbb93c65290 100644
--- a/chrome/browser/autocomplete/search_provider_unittest.cc
+++ b/chrome/browser/autocomplete/search_provider_unittest.cc
@@ -153,6 +153,10 @@ void SearchProviderTest::SetUp() {
   provider_ = new SearchProvider(this, &profile_);
 
   URLFetcher::set_factory(&test_factory_);
+
+  // Prevent the Instant field trial from kicking in.
+  PrefService* service = profile_.GetPrefs();
+  service->SetBoolean(prefs::kInstantEnabledOnce, true);
 }
 
 void SearchProviderTest::OnProviderUpdate(bool updated_matches) {
@@ -623,7 +627,7 @@ TEST_F(SearchProviderTest, UpdateKeywordDescriptions) {
   ACProviders providers;
   SearchProvider* provider = provider_.release();
   providers.push_back(provider);
-  AutocompleteController controller(providers);
+  AutocompleteController controller(providers, &profile_);
   controller.set_search_provider(provider);
   provider->set_listener(&controller);
   controller.Start(ASCIIToUTF16("k t"), string16(), false, false, true,