Re-land first pass BackgroundTracingManager.

content/public/browser/background_tracing_preemptive_config.cc

Index: content/public/browser/background_tracing_preemptive_config.cc
diff --git a/content/public/browser/background_tracing_preemptive_config.cc b/content/public/browser/background_tracing_preemptive_config.cc
new file mode 100644
index 0000000000000000000000000000000000000000..010109bec3c09a248fe913aaef59879a5ea92243
--- /dev/null
+++ b/content/public/browser/background_tracing_preemptive_config.cc
@@ -0,0 +1,17 @@
+// 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 "content/public/browser/background_tracing_preemptive_config.h"
+
+namespace content {
+
+BackgroundTracingPreemptiveConfig::BackgroundTracingPreemptiveConfig()
+    : BackgroundTracingConfig(BackgroundTracingConfig::PREEMPTIVE_TRACING_MODE),
+      category_preset(BackgroundTracingConfig::BENCHMARK) {
+}
+
+BackgroundTracingPreemptiveConfig::~BackgroundTracingPreemptiveConfig() {
+}
+
+}  // namespace content