[Extensions Bindings] Move safeCallbackApply to exception handler

extensions/renderer/resources/uncaught_exception_handler.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Handles uncaught exceptions thrown by extensions. By default this is to
 // log an error message, but tests may override this behaviour.
 var handler = function(message, e) {
   console.error(message);
 };
 
 /**
+ * Formats the error message and invokes the error handler.
+ *
+ * @param {string} message - Error message prefix.
+ * @param {Error|*} e - Thrown object.
+ * @param {string=} priorStackTrace - Error message suffix.
+ * @see formatErrorMessage
+ */
+function handle(message, e, priorStackTrace) {
+  message = formatErrorMessage(message, e, priorStackTrace);
+  handler(message, e);
+}
+
+// Runs a user-supplied callback safely.
+function safeCallbackApply(name, request, callback, args) {
+  try {
+    $Function.apply(callback, request, args);
+  } catch (e) {
+    handle('Error in response to ' + name, e, request.stack);
+  }
+}
+
+/**
  * Append the error description and stack trace to |message|.
  *
  * @param {string} message - The prefix of the error message.
  * @param {Error|*} e - The thrown error object. This object is potentially
  *   unsafe, because it could be generated by an extension.
  * @param {string=} priorStackTrace - The stack trace to be appended to the
  *   error message. This stack trace must not include stack frames of |e.stack|,
  *   because both stack traces are concatenated. Overlapping stack traces will
  *   confuse extension developers.
  * @return {string} The formatted error message.
@@ skipping 58 matching lines @@
 function safeErrorToString(e, omitType) {
   try {
     return $String.self(omitType && e.message || e);
   } catch (e) {
     // This error is exceptional and could be triggered by
     // throw {toString: function() { throw 'Haha' } };
     return '(cannot get error message)';
   }
 }
 
-/**
- * Formats the error message and invokes the error handler.
- *
- * @param {string} message - Error message prefix.
- * @param {Error|*} e - Thrown object.
- * @param {string=} priorStackTrace - Error message suffix.
- * @see formatErrorMessage
- */
-exports.$set('handle', function(message, e, priorStackTrace) {
-  message = formatErrorMessage(message, e, priorStackTrace);
-  handler(message, e);
-});
+exports.$set('handle', handle);
 
 // |newHandler| A function which matches |handler|.
 exports.$set('setHandler', function(newHandler) {
   handler = newHandler;
 });
 
+exports.$set('safeCallbackApply', safeCallbackApply);
 exports.$set('getStackTrace', getStackTrace);
 exports.$set('getExtensionStackTrace', getExtensionStackTrace);
 exports.$set('safeErrorToString', safeErrorToString);