Implement the filesystem proxy. This allows the FileRef tests to pass in the...

webkit/plugins/ppapi/ppb_file_ref_impl.cc

Index: webkit/plugins/ppapi/ppb_file_ref_impl.cc
===================================================================
--- webkit/plugins/ppapi/ppb_file_ref_impl.cc	(revision 75471)
+++ webkit/plugins/ppapi/ppb_file_ref_impl.cc	(working copy)
@@ -68,7 +68,7 @@
   scoped_refptr<PPB_FileRef_Impl> file_ref(
       Resource::GetAs<PPB_FileRef_Impl>(file_ref_id));
   if (!file_ref)
-    return PP_FILESYSTEMTYPE_EXTERNAL;
+    return PP_FILESYSTEMTYPE_NONE;
   return file_ref->GetFileSystemType();
 }
 
@@ -307,6 +307,8 @@
 }
 
 PP_FileSystemType_Dev PPB_FileRef_Impl::GetFileSystemType() const {
+  // When the file ref exists but there's no explicit filesystem object
+  // associated with it, that means it's an "external" filesystem.
   if (!file_system_)
     return PP_FILESYSTEMTYPE_EXTERNAL;