[Extensions] Finish freezing schema

chrome/renderer/resources/extensions/chrome_setting.js

Index: chrome/renderer/resources/extensions/chrome_setting.js
diff --git a/chrome/renderer/resources/extensions/chrome_setting.js b/chrome/renderer/resources/extensions/chrome_setting.js
index ef8114824875d4dc31707105eefde197b99643e2..77dfba5d5deca300a3958a46b6bb2e22ef7d27b3 100644
--- a/chrome/renderer/resources/extensions/chrome_setting.js
+++ b/chrome/renderer/resources/extensions/chrome_setting.js
@@ -12,6 +12,7 @@ function extendSchema(schema) {
   return extendedSchema;
 }
 
+// TODO(devlin): Maybe find a way to combine this and ContentSetting.
 function ChromeSetting(prefKey, valueSchema) {
   this.get = function(details, callback) {
     var getSchema = this.functionSchemas.get.definition.parameters;
@@ -21,13 +22,24 @@ function ChromeSetting(prefKey, valueSchema) {
                        extendSchema(getSchema));
   };
   this.set = function(details, callback) {
-    var setSchema = $Array.slice(
-        this.functionSchemas.set.definition.parameters);
-    setSchema[0].properties.value = valueSchema;
-    validate([details, callback], setSchema);
+    // The set schema included in the Schema object is generic, since it varies
+    // per-setting. However, this is only ever for a single setting, so we can
+    // enforce the types more thoroughly.
+    var rawSetSchema = this.functionSchemas.set.definition.parameters;

[Devlin, 2016/04/20 23:24:43]

Yucky stuff.  Mostly because all of this was yucky before, and now it's just
more verbosely yucky.  But at least now schema is fully frozen, and, unlike
tricky getter/setters, will throw if someone forgets to do something in the
future.

+    var rawSettingParam = rawSetSchema[0];
+    var props = $Object.assign({}, rawSettingParam.properties);
+    props.value = valueSchema;
+    var modSettingParam = {
+      name: rawSettingParam.name,
+      type: rawSettingParam.type,
+      properties: props,
+    };
+    var modSetSchema = $Array.slice(rawSetSchema);
+    modSetSchema[0] = modSettingParam;
+    validate([details, callback], modSetSchema);
     return sendRequest('types.ChromeSetting.set',
                        [prefKey, details, callback],
-                       extendSchema(setSchema));
+                       extendSchema(modSetSchema));
   };
   this.clear = function(details, callback) {
     var clearSchema = this.functionSchemas.clear.definition.parameters;