Prevent chrome.app JSON schema from loading on every page

chrome/renderer/extensions/chrome_v8_context.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/chrome_v8_context.h"
 
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string_split.h"
@@ skipping 136 matching lines @@
                                                    argc,
                                                    argv);
   if (result)
     *result = result_temp;
 
   return true;
 }
 
 Feature::Availability ChromeV8Context::GetAvailability(
     const std::string& api_name) {
+  return GetAvailabilityInternal(api_name, extension_);
+}
+
+Feature::Availability ChromeV8Context::GetAvailabilityForContext(
+    const std::string& api_name) {
+  return GetAvailabilityInternal(api_name, NULL);
+}
+
+Feature::Availability ChromeV8Context::GetAvailabilityInternal(
+    const std::string& api_name,
+    const Extension* extension) {
   return ExtensionAPI::GetSharedInstance()->IsAvailable(
       api_name,
-      extension_,
+      extension,
       context_type_,
       UserScriptSlave::GetDataSourceURLForFrame(web_frame_));
 }
 
 void ChromeV8Context::DispatchOnLoadEvent(bool is_incognito_process,
                                           int manifest_version) {
   v8::HandleScope handle_scope;
   v8::Handle<v8::Value> argv[] = {
     v8::String::New(GetExtensionID().c_str()),
     v8::String::New(GetContextTypeDescription().c_str()),
@@ skipping 47 matching lines @@
   // string if a validation error has occured.
   if (DCHECK_IS_ON()) {
     if (!retval.IsEmpty() && !retval->IsUndefined()) {
       std::string error = *v8::String::AsciiValue(retval);
       DCHECK(false) << error;
     }
   }
 }
 
 }  // namespace extensions