Register bindings for blessed web contexts (aka hosted app contexts) by hand

chrome/renderer/extensions/runtime_custom_bindings.cc

 // 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.
 
 #include "chrome/renderer/extensions/runtime_custom_bindings.h"
 
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/values.h"
 #include "chrome/common/extensions/extension_messages.h"
@@ skipping 40 matching lines @@
   // the correct source.
   content::RenderView* renderview = GetRenderView();
   if (!renderview)
     return;
 
   // The Javascript code should validate/fill the arguments.
   CHECK_EQ(args.Length(), 3);
   CHECK(args[0]->IsString() && args[1]->IsString() && args[2]->IsBoolean());
 
   ExtensionMsg_ExternalConnectionInfo info;
-  info.source_id = context()->GetExtensionID();
+
+  // For messaging APIs, hosted apps should be considered a web page so hide
+  // its extension ID.
+  const Extension* extension = context()->extension();
+  if (extension && !extension->is_hosted_app())
+    info.source_id = extension->id();
+
   info.target_id = *v8::String::Utf8Value(args[0]->ToString());
   info.source_url = context()->GetURL();
   std::string channel_name = *v8::String::Utf8Value(args[1]->ToString());
   bool include_tls_channel_id =
       args.Length() > 2 ? args[2]->BooleanValue() : false;
   int port_id = -1;
   renderview->Send(new ExtensionHostMsg_OpenChannelToExtension(
       renderview->GetRoutingID(), info, channel_name, include_tls_channel_id,
       &port_id));
   args.GetReturnValue().Set(static_cast<int32_t>(port_id));
@@ skipping 96 matching lines @@
       v8::Local<v8::Value> window = context->Global();
       DCHECK(!window.IsEmpty());
       v8_views->Set(v8::Integer::New(args.GetIsolate(), v8_index++), window);
     }
   }
 
   args.GetReturnValue().Set(v8_views);
 }
 
 }  // namespace extensions