Only set File::[tracing_]path_ when file tracing is enabled.

base/files/file.cc

 // 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.
 
 #include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/files/file_tracing.h"
 #include "base/metrics/histogram.h"
 #include "base/timer/elapsed_timer.h"
 
@@ skipping 34 matching lines @@
 }
 
 File::File(Error error_details)
     : error_details_(error_details),
       created_(false),
       async_(false) {
 }
 
 File::File(RValue other)
     : file_(other.object->TakePlatformFile()),
-      path_(other.object->path_),
+      tracing_path_(other.object->tracing_path_),
       error_details_(other.object->error_details()),
       created_(other.object->created()),
       async_(other.object->async_) {
 }
 
 File::~File() {
   // Go through the AssertIOAllowed logic.
   Close();
 }
 
 // static
 File File::CreateForAsyncHandle(PlatformFile platform_file) {
   File file(platform_file);
   // It would be nice if we could validate that |platform_file| was opened with
   // FILE_FLAG_OVERLAPPED on Windows but this doesn't appear to be possible.
   file.async_ = true;
   return file.Pass();
 }
 
 File& File::operator=(RValue other) {
   if (this != other.object) {
     Close();
     SetPlatformFile(other.object->TakePlatformFile());
-    path_ = other.object->path_;
+    tracing_path_ = other.object->tracing_path_;
     error_details_ = other.object->error_details();
     created_ = other.object->created();
     async_ = other.object->async_;
   }
   return *this;
 }
 
 #if !defined(OS_NACL)
 void File::Initialize(const FilePath& path, uint32 flags) {
   if (path.ReferencesParent()) {
     error_details_ = FILE_ERROR_ACCESS_DENIED;
     return;
   }
-  path_ = path;
+  if (FileTracing::IsCategoryEnabled())
+    tracing_path_ = path;
   SCOPED_FILE_TRACE("Initialize");
-  DoInitialize(flags);
+  DoInitialize(flags, path);
 }
 #endif
 
 std::string File::ErrorToString(Error error) {
   switch (error) {
     case FILE_OK:
       return "FILE_OK";
     case FILE_ERROR_FAILED:
       return "FILE_ERROR_FAILED";
     case FILE_ERROR_IN_USE:
@@ skipping 36 matching lines @@
 
 bool File::Flush() {
   ElapsedTimer timer;
   SCOPED_FILE_TRACE("Flush");
   bool return_value = DoFlush();
   UMA_HISTOGRAM_TIMES("PlatformFile.FlushTime", timer.Elapsed());
   return return_value;
 }
 
 }  // namespace base