[PPAPI] It is now possible to pass filesystems from JavaScript to NaCl modules.

ppapi/proxy/ppapi_messages.h

Index: ppapi/proxy/ppapi_messages.h
diff --git a/ppapi/proxy/ppapi_messages.h b/ppapi/proxy/ppapi_messages.h
index 02c4d84c51702254c5f6c2b8f3ac3dbc22a690a2..2313cf7074982b3b3c0d260d2fc5f51442f94473 100644
--- a/ppapi/proxy/ppapi_messages.h
+++ b/ppapi/proxy/ppapi_messages.h
@@ -1291,6 +1291,16 @@ IPC_MESSAGE_CONTROL0(PpapiPluginMsg_FileSystem_OpenReply)
 IPC_MESSAGE_CONTROL1(PpapiHostMsg_FileSystem_InitIsolatedFileSystem,
                      std::string /* fsid */)
 IPC_MESSAGE_CONTROL0(PpapiPluginMsg_FileSystem_InitIsolatedFileSystemReply)
+// Passed from renderer to browser. Creates an already-open file system with a
+// given |root_url| and |file_system_type|.
+IPC_MESSAGE_CONTROL2(PpapiHostMsg_FileSystem_CreateFromRenderer,
+                     std::string /* root_url */,
+                     PP_FileSystemType /* file_system_type */)
+// Nested within a ResourceVar for file systems being passed from the renderer
+// to the plugin. Creates an already-open file system resource on the plugin,
+// linked to the existing resource host given in the ResourceVar.
+IPC_MESSAGE_CONTROL1(PpapiPluginMsg_FileSystem_CreateFromPendingHost,
+                     PP_FileSystemType /* file_system_type */)
 
 // Flash DRM ------------------------------------------------------------------
 IPC_MESSAGE_CONTROL0(PpapiHostMsg_FlashDRM_Create)