Add the "options_ui" extension manifest field.

extensions/common/manifest_constants.cc

Index: extensions/common/manifest_constants.cc
diff --git a/extensions/common/manifest_constants.cc b/extensions/common/manifest_constants.cc
index 9aa20fd3f0531c433bd9d2e528116607185566fc..6cefb09697a547d15ca68ba9bb5568533da38aa5 100644
--- a/extensions/common/manifest_constants.cc
+++ b/extensions/common/manifest_constants.cc
@@ -95,6 +95,7 @@ const char kOmnibox[] = "omnibox";
 const char kOmniboxKeyword[] = "omnibox.keyword";
 const char kOptionalPermissions[] = "optional_permissions";
 const char kOptionsPage[] = "options_page";
+const char kOptionsUI[] = "options_ui";
 const char kOverrideHomepage[] = "chrome_settings_overrides.homepage";
 const char kOverrideSearchProvider[] =
     "chrome_settings_overrides.search_provider";
@@ -520,6 +521,16 @@ const char kInvalidOptionsPageExpectUrlInPackage[] =
 const char kInvalidOptionsPageInHostedApp[] =
     "Invalid value for 'options_page'. Hosted apps must specify an "
     "absolute URL.";
+const char kInvalidOptionsUIChromeStyle[] =
+    "Invalid value for 'options_ui.chrome_style'.";
+const char kInvalidOptionsUIOpenInTab[] =
+    "Invalid value for 'options_ui.open_in_tab'.";
+const char kInvalidOptionsUIPage[] = "Invalid value for 'options_ui.page'.";
+const char kInvalidOptionsUIPageExpectUrlInPackage[] =
+    "Invalid value for 'options_ui.page'.  Value must be a relative path.";
+const char kInvalidOptionsUIPageInHostedApp[] =
+    "Invalid value for 'options_ui.page'. Hosted apps must specify an "
+    "absolute URL.";
 const char kInvalidPageAction[] =
     "Invalid value for 'page_action'.";
 const char kInvalidPageActionDefaultTitle[] =