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

R=rvargas@chromium.org
BUG=none
TEST=less |path_| cruft lying around

Review URL: https://codereview.chromium.org/1216183004

Cr-Commit-Position: refs/heads/master@{#337168}


CrOS-Libchrome-Original-Commit: fd5b108c82d56f6022dfbe62a023d1e81ff6f83b
diff --git a/base/files/file_tracing.cc b/base/files/file_tracing.cc
index c25772d..92a5780 100644
--- a/base/files/file_tracing.cc
+++ b/base/files/file_tracing.cc
@@ -13,6 +13,11 @@
 }
 
 // static
+bool FileTracing::IsCategoryEnabled() {
+  return g_provider && g_provider->FileTracingCategoryIsEnabled();
+}
+
+// static
 void FileTracing::SetProvider(FileTracing::Provider* provider) {
   g_provider = provider;
 }
@@ -34,19 +39,11 @@
     g_provider->FileTracingEventEnd(name_, id_);
 }
 
-bool FileTracing::ScopedTrace::ShouldInitialize() const {
-  return g_provider && g_provider->FileTracingCategoryIsEnabled();
-}
-
 void FileTracing::ScopedTrace::Initialize(
     const char* name, File* file, int64 size) {
-  if (!g_provider)
-    return;
-
   id_ = &file->trace_enabler_;
   name_ = name;
-
-  g_provider->FileTracingEventBegin(name_, id_, file->path_, size);
+  g_provider->FileTracingEventBegin(name_, id_, file->tracing_path_, size);
 }
 
 }  // namespace base