Make File::Duplicate() const

base/files/file_tracing.cc

 // Copyright 2015 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 "base/files/file_tracing.h"
 
 #include "base/files/file.h"
 
 namespace base {
 
@@ skipping 22 matching lines @@
 }
 
 FileTracing::ScopedTrace::ScopedTrace() : id_(nullptr) {}
 
 FileTracing::ScopedTrace::~ScopedTrace() {
   if (id_ && g_provider)
     g_provider->FileTracingEventEnd(name_, id_);
 }
 
 void FileTracing::ScopedTrace::Initialize(const char* name,
-                                          File* file,
+                                          const File* file,
                                           int64_t size) {
   id_ = &file->trace_enabler_;
   name_ = name;
   g_provider->FileTracingEventBegin(name_, id_, file->tracing_path_, size);
 }
 
 }  // namespace base