Don't allow multiple opens for Pepper FileSystem.

webkit/plugins/ppapi/ppb_file_system_impl.cc

 // Copyright (c) 2010 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 "webkit/plugins/ppapi/ppb_file_system_impl.h"
 
 #include "base/ref_counted.h"
 #include "ppapi/c/dev/ppb_file_system_dev.h"
 #include "ppapi/c/pp_completion_callback.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebDocument.h"
@@ skipping 38 matching lines @@
 }
 
 int32_t Open(PP_Resource file_system_id,
              int64 expected_size,
              PP_CompletionCallback callback) {
   scoped_refptr<PPB_FileSystem_Impl> file_system(
       Resource::GetAs<PPB_FileSystem_Impl>(file_system_id));
   if (!file_system)
     return PP_ERROR_BADRESOURCE;
 
-  if (file_system->opened())
-    return PP_OK;
+  // Should not allow multiple opens.
+  if (file_system->called_open())
+    return PP_ERROR_FAILED;
+  file_system->set_called_open();
 
   if ((file_system->type() != PP_FILESYSTEMTYPE_LOCALPERSISTENT) &&
       (file_system->type() != PP_FILESYSTEMTYPE_LOCALTEMPORARY))
     return PP_ERROR_FAILED;
 
   PluginInstance* instance = file_system->instance();
   fileapi::FileSystemType file_system_type =
       (file_system->type() == PP_FILESYSTEMTYPE_LOCALTEMPORARY ?
        fileapi::kFileSystemTypeTemporary :
        fileapi::kFileSystemTypePersistent);
@@ skipping 22 matching lines @@
   &GetType
 };
 
 }  // namespace
 
 PPB_FileSystem_Impl::PPB_FileSystem_Impl(PluginInstance* instance,
                                          PP_FileSystemType_Dev type)
     : Resource(instance),
       instance_(instance),
       type_(type),
-      opened_(false) {
+      opened_(false),
+      called_open_(false) {
   DCHECK(type_ != PP_FILESYSTEMTYPE_INVALID);
 }
 
 PPB_FileSystem_Impl* PPB_FileSystem_Impl::AsPPB_FileSystem_Impl() {
   return this;
 }
 
 const PPB_FileSystem_Dev* PPB_FileSystem_Impl::GetInterface() {
   return &ppb_filesystem;
 }
 
 }  // namespace ppapi
 }  // namespace webkit