Re-land first pass BackgroundTracingManager.

content/public/browser/background_tracing_config.cc

Index: content/public/browser/background_tracing_config.cc
diff --git a/content/public/browser/interstitial_page_delegate.cc b/content/public/browser/background_tracing_config.cc
similarity index 52%
copy from content/public/browser/interstitial_page_delegate.cc
copy to content/public/browser/background_tracing_config.cc
index 60a441842b4af1ee688de6c4283e813f016059ec..e3c0c1b52b80d5167a91908436f8393152dc2ee2 100644
--- a/content/public/browser/interstitial_page_delegate.cc
+++ b/content/public/browser/background_tracing_config.cc
@@ -2,12 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "content/public/browser/interstitial_page_delegate.h"
+#include "content/public/browser/background_tracing_config.h"
 
 namespace content {
-InterstitialPageDelegate::TypeID InterstitialPageDelegate::GetTypeForTesting()
-    const {
-  return nullptr;
+
+BackgroundTracingConfig::BackgroundTracingConfig(Mode mode) : mode(mode) {
+}
+
+BackgroundTracingConfig::~BackgroundTracingConfig() {
 }
 
 }  // namespace content