Refactor direct_memory_pressure_calculator.h per platform.

components/memory_pressure/direct_memory_pressure_calculator.cc

Index: components/memory_pressure/direct_memory_pressure_calculator.cc
diff --git a/components/memory_pressure/direct_memory_pressure_calculator.cc b/components/memory_pressure/direct_memory_pressure_calculator.cc
deleted file mode 100644
index 88b5794c23fe32aa44cea953d914028c5ff1c354..0000000000000000000000000000000000000000
--- a/components/memory_pressure/direct_memory_pressure_calculator.cc
+++ /dev/null
@@ -1,18 +0,0 @@
-// 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 "components/memory_pressure/direct_memory_pressure_calculator.h"
-
-namespace memory_pressure {
-
-#if defined(MEMORY_PRESSURE_IS_POLLING)
-
-bool DirectMemoryPressureCalculator::GetSystemMemoryInfo(
-    base::SystemMemoryInfoKB* mem_info) const {
-  return base::GetSystemMemoryInfo(mem_info);
-}
-
-#endif  // defined(MEMORY_PRESSURE_IS_POLLING)
-
-}  // namespace memory_pressure