Signal extension API schema corruption to the browser process.

extensions/renderer/v8_schema_registry.cc

 // Copyright 2014 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 "extensions/renderer/v8_schema_registry.h"
 
 #include <stddef.h>
 
 #include <utility>
 
 #include "base/logging.h"
 #include "base/values.h"
 #include "content/public/child/v8_value_converter.h"
+#include "content/public/renderer/render_thread.h"
 #include "extensions/common/extension_api.h"
+#include "extensions/common/extension_messages.h"
 #include "extensions/renderer/object_backed_native_handler.h"
 #include "extensions/renderer/script_context.h"
 #include "extensions/renderer/v8_helpers.h"
 
 using content::V8ValueConverter;
 
 namespace extensions {
 
 namespace {
 
@@ skipping 99 matching lines @@
 
   // Slow path: Need to build schema first.
 
   v8::Isolate* isolate = v8::Isolate::GetCurrent();
   v8::EscapableHandleScope handle_scope(isolate);
   v8::Local<v8::Context> context = GetOrCreateContext(isolate);
   v8::Context::Scope context_scope(context);
 
   const base::DictionaryValue* schema =
       ExtensionAPI::GetSharedInstance()->GetSchema(api);
-  CHECK(schema) << api;
+
+  // If the schema for |api| cannot be loaded then return an empty object, but
+  // also notify the browser so that it can take appropriate action.
+  // See http://crbug.com/121424.
+  if (!schema) {
+    content::RenderThread::Get()->Send(
+        new ExtensionHostMsg_NotifyBadExtensionApiSchema(api));
+    return v8::Local<v8::Object>();
+  }
+
   std::unique_ptr<V8ValueConverter> v8_value_converter(
       V8ValueConverter::create());
   v8::Local<v8::Value> value = v8_value_converter->ToV8Value(schema, context);
   CHECK(!value.IsEmpty());
 
   v8::Local<v8::Object> v8_schema(v8::Local<v8::Object>::Cast(value));
   DeepFreeze(v8_schema, context);
   schema_cache_->Set(api, v8_schema);
 
   return handle_scope.Escape(v8_schema);
 }
 
 v8::Local<v8::Context> V8SchemaRegistry::GetOrCreateContext(
     v8::Isolate* isolate) {
   // It's ok to create local handles in this function, since this is only called
   // when we have a HandleScope.
   if (!context_holder_) {
     context_holder_.reset(new gin::ContextHolder(isolate));
     context_holder_->SetContext(v8::Context::New(isolate));
     schema_cache_.reset(new SchemaCache(isolate));
     return context_holder_->context();
   }
   return context_holder_->context();
 }
 
 }  // namespace extensions