Remove memory_pressure component.

components/memory_pressure/direct_memory_pressure_calculator_win.cc

-// 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_win.h"
-
-#include "base/logging.h"
-#include "base/process/process_metrics.h"
-
-namespace memory_pressure {
-
-#if defined(MEMORY_PRESSURE_IS_POLLING)
-
-namespace {
-
-const int kKBperMB = 1024;
-
-}  // namespace
-
-// A system is considered 'high memory' if it has more than 1.5GB of system
-// memory available for use by the memory manager (not reserved for hardware
-// and drivers). This is a fuzzy version of the ~2GB discussed below.
-const int DirectMemoryPressureCalculator::kLargeMemoryThresholdMb = 1536;
-
-// These are the default thresholds used for systems with < ~2GB of physical
-// memory. Such systems have been observed to always maintain ~100MB of
-// available memory, paging until that is the case. To try to avoid paging a
-// threshold slightly above this is chosen. The moderate threshold is slightly
-// less grounded in reality and chosen as 2.5x critical.
-const int
-    DirectMemoryPressureCalculator::kSmallMemoryDefaultModerateThresholdMb =
-        500;
-const int
-    DirectMemoryPressureCalculator::kSmallMemoryDefaultCriticalThresholdMb =
-        200;
-
-// These are the default thresholds used for systems with >= ~2GB of physical
-// memory. Such systems have been observed to always maintain ~300MB of
-// available memory, paging until that is the case.
-const int
-    DirectMemoryPressureCalculator::kLargeMemoryDefaultModerateThresholdMb =
-        1000;
-const int
-    DirectMemoryPressureCalculator::kLargeMemoryDefaultCriticalThresholdMb =
-        400;
-
-DirectMemoryPressureCalculator::DirectMemoryPressureCalculator()
-    : moderate_threshold_mb_(0), critical_threshold_mb_(0) {
-  InferThresholds();
-}
-
-DirectMemoryPressureCalculator::DirectMemoryPressureCalculator(
-    int moderate_threshold_mb,
-    int critical_threshold_mb)
-    : moderate_threshold_mb_(moderate_threshold_mb),
-      critical_threshold_mb_(critical_threshold_mb) {
-  DCHECK_GE(moderate_threshold_mb_, critical_threshold_mb_);
-  DCHECK_LE(0, critical_threshold_mb_);
-}
-
-DirectMemoryPressureCalculator::MemoryPressureLevel
-DirectMemoryPressureCalculator::CalculateCurrentPressureLevel() {
-  base::SystemMemoryInfoKB mem_info = {};
-  if (!GetSystemMemoryInfo(&mem_info))
-    return MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE;
-
-  // How much system memory is actively available for use right now, in MBs.
-  int phys_free = mem_info.avail_phys / kKBperMB;
-
-  // TODO(chrisha): This should eventually care about address space pressure,
-  // but the browser process (where this is running) effectively never runs out
-  // of address space. Renderers occasionally do, but it does them no good to
-  // have the browser process monitor address space pressure. Long term,
-  // renderers should run their own address space pressure monitors and act
-  // accordingly, with the browser making cross-process decisions based on
-  // system memory pressure.
-
-  // Determine if the physical memory is under critical memory pressure.
-  if (phys_free <= critical_threshold_mb_)
-    return MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL;
-
-  // Determine if the physical memory is under moderate memory pressure.
-  if (phys_free <= moderate_threshold_mb_)
-    return MemoryPressureListener::MEMORY_PRESSURE_LEVEL_MODERATE;
-
-  // No memory pressure was detected.
-  return MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE;
-}
-
-bool DirectMemoryPressureCalculator::GetSystemMemoryInfo(
-    base::SystemMemoryInfoKB* mem_info) const {
-  return base::GetSystemMemoryInfo(mem_info);
-}
-
-void DirectMemoryPressureCalculator::InferThresholds() {
-  // Determine if the memory installed is 'large' or 'small'. Default to 'large'
-  // on failure, which uses more conservative thresholds.
-  bool large_memory = true;
-  base::SystemMemoryInfoKB mem_info = {};
-  if (GetSystemMemoryInfo(&mem_info)) {
-    large_memory = mem_info.total / kKBperMB >=
-                   DirectMemoryPressureCalculator::kLargeMemoryThresholdMb;
-  }
-
-  if (large_memory) {
-    moderate_threshold_mb_ = kLargeMemoryDefaultModerateThresholdMb;
-    critical_threshold_mb_ = kLargeMemoryDefaultCriticalThresholdMb;
-  } else {
-    moderate_threshold_mb_ = kSmallMemoryDefaultModerateThresholdMb;
-    critical_threshold_mb_ = kSmallMemoryDefaultCriticalThresholdMb;
-  }
-}
-
-#endif  // defined(MEMORY_PRESSURE_IS_POLLING)
-
-}  // namespace memory_pressure