Cleanup unused utils (#832)

* Remove api.optionsSave

* Remove getOptionsMutable and getOptionsFullMutable

* Remove util.js

* Remove yomichanBackend

2 files changed, 0 insertions, 9 deletions

diff --git a/ext/mixed/js/api.js b/ext/mixed/js/api.js
index ad5846fa..ca4d5732 100644
--- a/ext/mixed/js/api.js
+++ b/ext/mixed/js/api.js
@@ -57,10 +57,6 @@ const api = (() => {
             return this._invoke('optionsGetFull');
         }
 
-        optionsSave(source) {
-            return this._invoke('optionsSave', {source});
-        }
-
         termsFind(text, details, optionsContext) {
             return this._invoke('termsFind', {text, details, optionsContext});
         }
diff --git a/ext/mixed/js/core.js b/ext/mixed/js/core.js
index 8b044a67..351d9371 100644
--- a/ext/mixed/js/core.js
+++ b/ext/mixed/js/core.js
@@ -192,11 +192,6 @@ const clone = (() => {
     return clone;
 })();
 
-// Expose clone function on the global object, since util.js's utilBackgroundIsolate needs access to it.
-if (typeof window === 'object' && window !== null) {
-    window.clone = clone;
-}
-
 function generateId(length) {
     const array = new Uint8Array(length);
     crypto.getRandomValues(array);