Do not dereference potentially invalid frame pointer.

chrome/renderer/extensions/bindings_utils.cc

 // Copyright (c) 2011 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 "chrome/renderer/extensions/bindings_utils.h"
 
 #include "base/logging.h"
 #include "base/lazy_instance.h"
 #include "base/stringprintf.h"
 #include "base/string_split.h"
@@ skipping 115 matching lines @@
 
   LOG(ERROR) << JoinString(components, ',');
   return v8::Undefined();
 }
 
 ContextInfo::ContextInfo(v8::Persistent<v8::Context> context,
                          const std::string& extension_id,
                          WebFrame* frame)
     : context(context),
       extension_id(extension_id),
-      frame(frame),
+      unsafe_frame(frame),
       num_connected_events(0) {
 }
 
 ContextInfo::~ContextInfo() {}
 
 ContextList& GetContexts() {
   return g_singleton_data.Get().contexts;
 }
 
 ContextInfo* GetInfoForCurrentContext() {
@@ skipping 69 matching lines @@
   }
 
   v8::Local<v8::Function> function = v8::Local<v8::Function>::Cast(value);
   if (!function.IsEmpty())
     return function->Call(v8::Object::New(), argc, argv);
 
   return v8::Undefined();
 }
 
 }  // namespace bindings_utils