bindings: Adds ASSERTs to check the creation context passed to public APIs.

Source/web/WebDOMFileSystem.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 98 matching lines @@
         return WebFileSystem::TypeTemporary;
     }
 }
 
 WebURL WebDOMFileSystem::rootURL() const
 {
     ASSERT(m_private.get());
     return m_private->rootURL();
 }
 
-v8::Local<v8::Value> WebDOMFileSystem::toV8Value(v8::Local<v8::Object> /* creationContext */, v8::Isolate* isolate)
+v8::Local<v8::Value> WebDOMFileSystem::toV8Value(v8::Local<v8::Object> creationContext, v8::Isolate* isolate)
 {
     // We no longer use |creationContext| because it's often misused and points
     // to a context faked by user script.
+    ASSERT(creationContext->CreationContext() == isolate->GetCurrentContext());
     if (!m_private.get())
         return v8::Local<v8::Value>();
     return toV8(m_private.get(), isolate->GetCurrentContext()->Global(), isolate);
 }
 
 v8::Local<v8::Value> WebDOMFileSystem::createV8Entry(
     const WebString& path,
     EntryType entryType,
     v8::Local<v8::Object> creationContext,
     v8::Isolate* isolate)
 {
+    // We no longer use |creationContext| because it's often misused and points
+    // to a context faked by user script.
+    ASSERT(creationContext->CreationContext() == isolate->GetCurrentContext());
     if (!m_private.get())
         return v8::Local<v8::Value>();
     if (entryType == EntryTypeDirectory)
         return toV8(DirectoryEntry::create(m_private.get(), path), isolate->GetCurrentContext()->Global(), isolate);
     ASSERT(entryType == EntryTypeFile);
     return toV8(FileEntry::create(m_private.get(), path), isolate->GetCurrentContext()->Global(), isolate);
 }
 
 WebDOMFileSystem::WebDOMFileSystem(DOMFileSystem* domFileSystem)
     : m_private(domFileSystem)
 {
 }
 
 WebDOMFileSystem& WebDOMFileSystem::operator=(DOMFileSystem* domFileSystem)
 {
     m_private = domFileSystem;
     return *this;
 }
 
 } // namespace blink