Sang's initial CL for moving the file interface out of dev.

ppapi/c/ppb_file_system.h

Index: ppapi/c/ppb_file_system.h
===================================================================
--- ppapi/c/ppb_file_system.h	(revision 0)
+++ ppapi/c/ppb_file_system.h	(revision 0)
@@ -0,0 +1,47 @@
+/* Copyright (c) 2011 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 PPAPI_C_PPB_FILE_SYSTEM_H_
+#define PPAPI_C_PPB_FILE_SYSTEM_H_
+
+#include "ppapi/c/pp_bool.h"
+#include "ppapi/c/pp_file_info.h"
+#include "ppapi/c/pp_instance.h"
+#include "ppapi/c/pp_resource.h"
+#include "ppapi/c/pp_stdint.h"
+#include "ppapi/c/pp_time.h"
+
+struct PP_CompletionCallback;
+
+#define PPB_FILESYSTEM_INTERFACE_0_6 "PPB_FileSystem;0.6"
+#define PPB_FILESYSTEM_INTERFACE PPB_FILESYSTEM_INTERFACE_0_6
+
+struct PPB_FileSystem {
+  /** Creates a filesystem object of the given type. */
+  PP_Resource (*Create)(PP_Instance instance, PP_FileSystemType type);
+
+  /** Returns PP_TRUE if the given resource is a FileSystem. */
+  PP_Bool (*IsFileSystem)(PP_Resource resource);
+
+  /**
+   * Opens the file system. A file system must be opened before running any
+   * other operation on it.
+   *
+   * TODO(brettw) clarify whether this must have completed before a file can
+   * be opened in it. Clarify what it means to be "completed."
+   */
+  int32_t (*Open)(PP_Resource file_system,
+                  int64_t expected_size,
+                  struct PP_CompletionCallback callback);
+
+  /**
+   * Returns the type of the given file system.
+   *
+   * Returns PP_FILESYSTEMTYPE_INVALID if the given resource is not a valid
+   * filesystem. It is valid to call this function even before Open completes.
+   */
+  PP_FileSystemType (*GetType)(PP_Resource file_system);
+};
+
+#endif  /* PPAPI_C_PPB_FILE_SYSTEM_H_ */