Remove obsolete try/catch from ObjectIsPromise().

src/debug/mirrors.js

 // Copyright 2006-2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 (function(global, utils) {
 "use strict";
 
 // ----------------------------------------------------------------------------
 // Imports
 
@@ skipping 89 matching lines @@
   ClearMirrorCache();
 }
 
 
 function ClearMirrorCache(value) {
   next_handle_ = 0;
   mirror_cache_ = [];
 }
 
 
-// Wrapper to check whether an object is a Promise.  The call may not work
-// if promises are not enabled.
-// TODO(yangguo): remove try-catch once promises are enabled by default.
 function ObjectIsPromise(value) {
-  try {
-    return IS_SPEC_OBJECT(value) &&
-           !IS_UNDEFINED(%DebugGetProperty(value, promiseStatusSymbol));
-  } catch (e) {
-    return false;
-  }
+  return IS_SPEC_OBJECT(value) &&
+         !IS_UNDEFINED(%DebugGetProperty(value, promiseStatusSymbol));
 }
 
 
 /**
  * Returns the mirror for a specified value or object.
  *
  * @param {value or Object} value the value or object to retreive the mirror for
  * @param {boolean} transient indicate whether this object is transient and
  *    should not be added to the mirror cache. The default is not transient.
  * @returns {Mirror} the mirror reflects the passed value or object
@@ skipping 2981 matching lines @@
 // Functions needed by the debugger runtime.
 utils.InstallFunctions(utils, DONT_ENUM, [
   "ClearMirrorCache", ClearMirrorCache
 ]);
 
 // Export to debug.js
 utils.Export(function(to) {
   to.MirrorType = MirrorType;
 });
 })