Use the DefaultSearchManager as the exclusive authority on DSE, ignoring Web Data.

chrome/browser/search_engines/search_provider_install_data.cc

Index: chrome/browser/search_engines/search_provider_install_data.cc
diff --git a/chrome/browser/search_engines/search_provider_install_data.cc b/chrome/browser/search_engines/search_provider_install_data.cc
index 64b14fdebde2dde07e9148a52bbde1b54d027017..6c1e6a518f3c16a2ad5e388139f52dadff26aa92 100644
--- a/chrome/browser/search_engines/search_provider_install_data.cc
+++ b/chrome/browser/search_engines/search_provider_install_data.cc
@@ -249,19 +249,23 @@ void SearchProviderInstallData::OnWebDataServiceRequestDone(
     return;
   }
 
-  TemplateURL* default_search_provider = NULL;
   int new_resource_keyword_version = 0;
   std::vector<TemplateURL*> extracted_template_urls;
-  GetSearchProvidersUsingKeywordResult(*result, NULL, NULL,
-      &extracted_template_urls, &default_search_provider,
-      &new_resource_keyword_version, NULL);
+  GetSearchProvidersUsingKeywordResult(*result,
+                                       NULL,
+                                       NULL,
+                                       &extracted_template_urls,
+                                       NULL,
+                                       &new_resource_keyword_version,
+                                       NULL);
   template_urls_.get().insert(template_urls_.get().begin(),
                               extracted_template_urls.begin(),
                               extracted_template_urls.end());
   IOThreadSearchTermsData search_terms_data(google_base_url_);
   provider_map_.reset(new SearchHostToURLsMap());
   provider_map_->Init(template_urls_.get(), search_terms_data);
-  SetDefault(default_search_provider);
+  // TODO(erikwright): This needs to be based on prefs now...
+  SetDefault(NULL);

[Peter Kasting, 2014/05/03 00:28:18]

Um, what is the effect of not getting this right today?  "SetDefault(NULL)"
worries me that you're going to break something important.

[erikwright (departed), 2014/05/05 01:49:38]

I intend to resolve this TODO before committing.

   NotifyLoaded();
 }