MD Settings: clarify "controlled by" logic

chrome/browser/extensions/settings_api_helpers.cc

Index: chrome/browser/extensions/settings_api_helpers.cc
diff --git a/chrome/browser/extensions/settings_api_helpers.cc b/chrome/browser/extensions/settings_api_helpers.cc
index f7a60bff3a2c441cfb026f312240ca65adf1da48..6e03168dd4ca7022a8e3e99dfb13f64e11bc59c8 100644
--- a/chrome/browser/extensions/settings_api_helpers.cc
+++ b/chrome/browser/extensions/settings_api_helpers.cc
@@ -6,12 +6,16 @@
 
 #include "chrome/browser/extensions/api/preference/preference_api.h"
 #include "chrome/common/pref_names.h"
+#include "chrome/common/url_constants.h"
 #include "components/proxy_config/proxy_config_pref_names.h"
 #include "components/search_engines/search_engines_pref_names.h"
+#include "content/public/browser/browser_url_handler.h"
 #include "extensions/browser/extension_pref_value_map.h"
 #include "extensions/browser/extension_pref_value_map_factory.h"
 #include "extensions/browser/extension_registry.h"
+#include "extensions/common/constants.h"
 #include "extensions/common/extension_set.h"
+#include "url/gurl.h"
 
 namespace extensions {
 
@@ -71,6 +75,19 @@ const Extension* GetExtensionOverridingHomepage(
   return FindOverridingExtension(browser_context, BUBBLE_TYPE_HOME_PAGE);
 }
 
+const Extension* GetExtensionOverridingNewTabPage(
+    content::BrowserContext* browser_context) {
+  GURL ntp_url(chrome::kChromeUINewTabURL);
+  bool ignored;
+  content::BrowserURLHandler::GetInstance()->RewriteURLIfNecessary(
+      &ntp_url, browser_context, &ignored);
+  if (ntp_url.SchemeIs(kExtensionScheme)) {
+    return ExtensionRegistry::Get(browser_context)->GetExtensionById(
+        ntp_url.host(), ExtensionRegistry::ENABLED);
+  }
+  return nullptr;
+}
+
 const Extension* GetExtensionOverridingStartupPages(
     content::BrowserContext* browser_context) {
   return FindOverridingExtension(browser_context, BUBBLE_TYPE_STARTUP_PAGES);