Remove memory_pressure component.

components/memory_pressure/memory_pressure_stats_collector.cc

Index: components/memory_pressure/memory_pressure_stats_collector.cc
diff --git a/components/memory_pressure/memory_pressure_stats_collector.cc b/components/memory_pressure/memory_pressure_stats_collector.cc
deleted file mode 100644
index b4ff482bd4e0331fc00d9f2a9c0e4878dd807400..0000000000000000000000000000000000000000
--- a/components/memory_pressure/memory_pressure_stats_collector.cc
+++ /dev/null
@@ -1,124 +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/memory_pressure_stats_collector.h"
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include "base/macros.h"
-#include "base/metrics/histogram_macros.h"
-#include "base/time/tick_clock.h"
-
-namespace memory_pressure {
-
-namespace {
-
-using MemoryPressureLevel = MemoryPressureListener::MemoryPressureLevel;
-
-// Converts a memory pressure level to an UMA enumeration value.
-MemoryPressureLevelUMA MemoryPressureLevelToUmaEnumValue(
-    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;
-}
-
-// Converts an UMA enumeration value to a memory pressure level.
-MemoryPressureLevel MemoryPressureLevelFromUmaEnumValue(
-    MemoryPressureLevelUMA level) {
-  switch (level) {
-    case UMA_MEMORY_PRESSURE_LEVEL_NONE:
-      return MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE;
-    case UMA_MEMORY_PRESSURE_LEVEL_MODERATE:
-      return MemoryPressureListener::MEMORY_PRESSURE_LEVEL_MODERATE;
-    case UMA_MEMORY_PRESSURE_LEVEL_CRITICAL:
-      return MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL;
-    case UMA_MEMORY_PRESSURE_LEVEL_COUNT:
-      NOTREACHED();
-      break;
-  }
-  NOTREACHED();
-  return MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE;
-}
-
-}  // namespace
-
-MemoryPressureStatsCollector::MemoryPressureStatsCollector(
-    base::TickClock* tick_clock)
-    : tick_clock_(tick_clock),
-      last_pressure_level_(MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE) {
-}
-
-void MemoryPressureStatsCollector::UpdateStatistics(
-    MemoryPressureLevel current_pressure_level) {
-  base::TimeTicks now = tick_clock_->NowTicks();
-
-  // Special case: first call to the collector. Observations have just started
-  // so there's nothing to report.
-  if (last_update_time_.is_null()) {
-    last_pressure_level_ = current_pressure_level;
-    last_update_time_ = now;
-    return;
-  }
-
-  // If the pressure level has transitioned then report this.
-  if (last_pressure_level_ != current_pressure_level)
-    ReportLevelChange(last_pressure_level_, current_pressure_level);
-
-  // Increment the appropriate cumulative bucket.
-  int index = MemoryPressureLevelToUmaEnumValue(current_pressure_level);
-  unreported_cumulative_time_[index] += now - last_update_time_;
-
-  // Update last pressure related state.
-  last_pressure_level_ = current_pressure_level;
-  last_update_time_ = now;
-
-  // Make reports about the amount of time spent cumulatively at each level.
-  for (size_t i = 0; i < arraysize(unreported_cumulative_time_); ++i) {
-    // Report the largest number of whole seconds possible at this moment and
-    // carry around the rest for a future report.
-    if (unreported_cumulative_time_[i].is_zero())
-      continue;
-    int64_t seconds = unreported_cumulative_time_[i].InSeconds();
-    if (seconds == 0)
-      continue;
-    unreported_cumulative_time_[i] -= base::TimeDelta::FromSeconds(seconds);
-
-    ReportCumulativeTime(MemoryPressureLevelFromUmaEnumValue(
-                             static_cast<MemoryPressureLevelUMA>(i)),
-                         static_cast<int>(seconds));
-  }
-}
-
-// static
-void MemoryPressureStatsCollector::ReportCumulativeTime(
-    MemoryPressureLevel pressure_level,
-    int seconds) {
-  // Use the more primitive STATIC_HISTOGRAM_POINTER_BLOCK macro because the
-  // simple UMA_HISTOGRAM macros don't expose 'AddCount' functionality.
-  STATIC_HISTOGRAM_POINTER_BLOCK(
-      "Memory.PressureLevel",
-      AddCount(MemoryPressureLevelToUmaEnumValue(pressure_level), seconds),
-      base::LinearHistogram::FactoryGet(
-          "Memory.PressureLevel", 1, UMA_MEMORY_PRESSURE_LEVEL_COUNT,
-          UMA_MEMORY_PRESSURE_LEVEL_COUNT + 1,
-          base::HistogramBase::kUmaTargetedHistogramFlag));
-}
-
-// static
-void MemoryPressureStatsCollector::ReportLevelChange(
-    MemoryPressureLevel old_pressure_level,
-    MemoryPressureLevel new_pressure_level) {
-  // TODO(chrisha): Report Memory.PressureLevelChange when this code is in use.
-}
-
-}  // namespace memory_pressure