Check for specific PPB interface versions in C++ wrappers.

ppapi/cpp/module.cc

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
 // Note that the single accessor, Module::Get(), is not actually implemented
 // in this file.  This is an intentional hook that allows users of ppapi's
-// C++ wrapper objects to provide difference semantics for how the singleton
+// C++ wrapper objects to provide different semantics for how the singleton
 // object is accessed.
 //
 // In general, users of ppapi will also link in ppp_entrypoints.cc, which
 // provides a simple default implementation of Module::Get().
 //
 // A notable exception where the default ppp_entrypoints will not work is
 // when implementing "internal plugins" that are statically linked into the
 // browser. In this case, the process may actually have multiple Modules
 // loaded at once making a traditional "singleton" unworkable.  To get around
 // this, the users of ppapi need to get creative about how to properly
@@ skipping 192 matching lines @@
   const PPB_Core* core = reinterpret_cast<const PPB_Core*>(GetBrowserInterface(
       PPB_CORE_INTERFACE));
   if (!core)
     return false;
   core_ = new Core(core);
 
   return Init();
 }
 
 }  // namespace pp