Verify that ComponentExtensionResourceManager exists before using it.

extensions/browser/api/execute_code_function.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.
 
 #ifndef EXTENSIONS_BROWSER_API_EXECUTE_CODE_FUNCTION_IMPL_H_
 #define EXTENSIONS_BROWSER_API_EXECUTE_CODE_FUNCTION_IMPL_H_
 
 #include "extensions/browser/api/execute_code_function.h"
 
 #include "extensions/browser/component_extension_resource_manager.h"
@@ skipping 188 matching lines @@
   if (!details_->file.get())
     return false;
   resource_ = extension()->GetResource(*details_->file);
 
   if (resource_.extension_root().empty() || resource_.relative_path().empty()) {
     error_ = kNoCodeOrFileToExecuteError;
     return false;
   }
 
   int resource_id;
-  if (ExtensionsBrowserClient::Get()
-          ->GetComponentExtensionResourceManager()
-          ->IsComponentExtensionResource(resource_.extension_root(),
-                                         resource_.relative_path(),
-                                         &resource_id)) {
+  ComponentExtensionResourceManager* component_extension_resource_manager =
+      ExtensionsBrowserClient::Get()->GetComponentExtensionResourceManager();
+  if (component_extension_resource_manager &&
+      component_extension_resource_manager->IsComponentExtensionResource(
+          resource_.extension_root(),
+          resource_.relative_path(),
+          &resource_id)) {
     const ResourceBundle& rb = ResourceBundle::GetSharedInstance();
     DidLoadFile(true, rb.GetRawDataResource(resource_id).as_string());
   } else {
     scoped_refptr<FileReader> file_reader(new FileReader(
         resource_, base::Bind(&ExecuteCodeFunction::DidLoadFile, this)));
     file_reader->Start();
   }
 
   return true;
 }
 
 void ExecuteCodeFunction::OnExecuteCodeFinished(const std::string& error,
                                                 const GURL& on_url,
                                                 const base::ListValue& result) {
   if (!error.empty())
     SetError(error);
 
   SendResponse(error.empty());
 }
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_EXECUTE_CODE_FUNCTION_IMPL_H_