Remove stale references to PlatformFile flags, errors or functions.

ppapi/proxy/file_io_resource.cc

Index: ppapi/proxy/file_io_resource.cc
diff --git a/ppapi/proxy/file_io_resource.cc b/ppapi/proxy/file_io_resource.cc
index 61b1a2037ec46518710024c3ea523af8fef1d0cd..29335ba90f49f9066e36aca2ee48739d64fda990 100644
--- a/ppapi/proxy/file_io_resource.cc
+++ b/ppapi/proxy/file_io_resource.cc
@@ -93,8 +93,8 @@ FileIOResource::WriteOp::~WriteOp() {
 }
 
 int32_t FileIOResource::WriteOp::DoWork() {
-  // In append mode, we can't call WritePlatformFile, since NaCl doesn't
-  // implement fcntl, causing the function to call pwrite, which is incorrect.
+  // In append mode, we can't call Write, since NaCl doesn't implement fcntl,
+  // causing the function to call pwrite, which is incorrect.
   if (append_) {
     return file_holder_->file()->WriteAtCurrentPos(buffer_.get(),
                                                    bytes_to_write_);