Unify logic of stack trace generation for extension errors

extensions/renderer/module_system.cc

 // 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.
 
 #include "extensions/renderer/module_system.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/stl_util.h"
@@ skipping 534 matching lines @@
 }
 
 v8::Handle<v8::String> ModuleSystem::WrapSource(v8::Handle<v8::String> source) {
   v8::EscapableHandleScope handle_scope(GetIsolate());
   // Keep in order with the arguments in RequireForJsInner.
   v8::Handle<v8::String> left = v8::String::NewFromUtf8(
       GetIsolate(),
       "(function(define, require, requireNative, requireAsync, exports, "
       "console, privates,"
       "$Array, $Function, $JSON, $Object, $RegExp, $String) {"
-      "'use strict';");
+      "'use strict';"
+      // Prevent extensions from overriding the Error constructor.
+      // Use window.Error instead of $Error to make sure that extensions can
+      // still use "instanceof Error" for exception handling.
+      "var Error = window.Error;");
   v8::Handle<v8::String> right = v8::String::NewFromUtf8(GetIsolate(), "\n})");
   return handle_scope.Escape(v8::Local<v8::String>(
       v8::String::Concat(left, v8::String::Concat(source, right))));
 }
 
 void ModuleSystem::Private(const v8::FunctionCallbackInfo<v8::Value>& args) {
   CHECK_EQ(1, args.Length());
   CHECK(args[0]->IsObject());
   v8::Local<v8::Object> obj = args[0].As<v8::Object>();
   v8::Local<v8::String> privates_key =
@@ skipping 94 matching lines @@
     v8::Handle<v8::Value> value) {
   if (!is_valid())
     return;
   v8::HandleScope handle_scope(GetIsolate());
   v8::Handle<v8::Promise::Resolver> resolver_local(
       v8::Local<v8::Promise::Resolver>::New(GetIsolate(), *resolver));
   resolver_local->Resolve(value);
 }
 
 }  // namespace extensions