Add Mac memory pressure statistic reporting and consolidate platform code

base/memory/memory_pressure_monitor_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 "base/memory/memory_pressure_monitor_win.h"
 
 #include <windows.h>
 
-#include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 
 namespace base {
 namespace win {
 
 namespace {
 
 static const DWORDLONG kMBBytes = 1024 * 1024;
 
-// Enumeration of UMA memory pressure levels. This needs to be kept in sync with
-// histograms.xml and the memory pressure levels defined in
-// MemoryPressureListener.
-enum MemoryPressureLevelUMA {
-  UMA_MEMORY_PRESSURE_LEVEL_NONE = 0,
-  UMA_MEMORY_PRESSURE_LEVEL_MODERATE = 1,
-  UMA_MEMORY_PRESSURE_LEVEL_CRITICAL = 2,
-  // This must be the last value in the enum.
-  UMA_MEMORY_PRESSURE_LEVEL_COUNT,
-};
-
-// Converts a memory pressure level to an UMA enumeration value.
-MemoryPressureLevelUMA MemoryPressureLevelToUmaEnumValue(
-    MemoryPressureListener::MemoryPressureLevel level) {
-  switch (level) {
-    case MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE:
-      return UMA_MEMORY_PRESSURE_LEVEL_NONE;
-    case MemoryPressureListener::MEMORY_PRESSURE_LEVEL_MODERATE:
-      return UMA_MEMORY_PRESSURE_LEVEL_MODERATE;
-    case MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL:
-      return UMA_MEMORY_PRESSURE_LEVEL_CRITICAL;
-  }
-  NOTREACHED();
-  return UMA_MEMORY_PRESSURE_LEVEL_NONE;
-}
-
 }  // namespace
 
 // The following constants have been lifted from similar values in the ChromeOS
 // memory pressure monitor. The values were determined experimentally to ensure
 // sufficient responsiveness of the memory pressure subsystem, and minimal
 // overhead.
 const int MemoryPressureMonitor::kPollingIntervalMs = 5000;
 const int MemoryPressureMonitor::kModeratePressureCooldownMs = 10000;
 const int MemoryPressureMonitor::kModeratePressureCooldownCycles =
     kModeratePressureCooldownMs / kPollingIntervalMs;
@@ skipping 146 matching lines @@
   DCHECK_NE(MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE,
             current_memory_pressure_level_);
   dispatch_callback_.Run(current_memory_pressure_level_);
 }
 
 void MemoryPressureMonitor::CheckMemoryPressureAndRecordStatistics() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   CheckMemoryPressure();
 
-  UMA_HISTOGRAM_ENUMERATION(
-      "Memory.PressureLevel",
-      MemoryPressureLevelToUmaEnumValue(current_memory_pressure_level_),
-      UMA_MEMORY_PRESSURE_LEVEL_COUNT);
+  RecordMemoryPressure(current_memory_pressure_level_, 1);
 }
 
 MemoryPressureListener::MemoryPressureLevel
 MemoryPressureMonitor::CalculateCurrentPressureLevel() {
   MEMORYSTATUSEX mem_status = {};
   if (!GetSystemMemoryStatus(&mem_status))
     return MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE;
 
   // How much system memory is actively available for use right now, in MBs.
   int phys_free = static_cast<int>(mem_status.ullAvailPhys / kMBBytes);
@@ skipping 27 matching lines @@
   return true;
 }
 
 void MemoryPressureMonitor::SetDispatchCallback(
     const DispatchCallback& callback) {
   dispatch_callback_ = callback;
 }
 
 }  // namespace win
 }  // namespace base