memory coordinator: Purge memory under memory pressure

content/public/browser/memory_coordinator_delegate.cc

Index: content/public/browser/memory_coordinator_delegate.cc
diff --git a/content/public/browser/memory_coordinator_delegate.cc b/content/public/browser/memory_coordinator_delegate.cc
new file mode 100644
index 0000000000000000000000000000000000000000..03ba1185c85ed074eaa5b72c8ef7ac6deafc2cf2
--- /dev/null
+++ b/content/public/browser/memory_coordinator_delegate.cc
@@ -0,0 +1,13 @@
+// Copyright 2017 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/memory_coordinator_delegate.h"
+
+namespace content {
+
+bool MemoryCoordinatorDelegate::DiscardTab() {
+  return false;
+}
+
+}  // namespace content