Extract guts of ChromeStabilityMetricsProvider into helper class

chrome/browser/memory/system_memory_stats_recorder_linux.cc

Index: chrome/browser/memory/system_memory_stats_recorder_linux.cc
diff --git a/chrome/browser/memory/system_memory_stats_recorder_linux.cc b/chrome/browser/memory/system_memory_stats_recorder_linux.cc
deleted file mode 100644
index fbec6ef4d5c88ba56991a57521a18e427a8023b0..0000000000000000000000000000000000000000
--- a/chrome/browser/memory/system_memory_stats_recorder_linux.cc
+++ /dev/null
@@ -1,97 +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 "chrome/browser/memory/system_memory_stats_recorder.h"
-
-#include "base/metrics/histogram_macros.h"
-#include "base/process/process_metrics.h"
-
-namespace memory {
-
-// Record a size in megabytes, a potential interval from 250MB up to 32 GB.
-#define UMA_HISTOGRAM_ALLOCATED_MEGABYTES(name, sample) \
-  UMA_HISTOGRAM_CUSTOM_COUNTS(name, sample, 250, 32768, 50)
-
-// Records a statistics |sample| for UMA histogram |name|
-// using a linear distribution of buckets.
-#define UMA_HISTOGRAM_LINEAR(name, sample, max, buckets)                       \
-  STATIC_HISTOGRAM_POINTER_BLOCK(                                              \
-      name, Add(sample),                                                       \
-      base::LinearHistogram::FactoryGet(                                       \
-          name,                                                                \
-          1, /* Minimum. The 0 bin for underflow is automatically added. */    \
-          max + 1,     /* Ensure bucket size of |maximum| / |bucket_count|. */ \
-          buckets + 2, /*  Account for the underflow and overflow bins. */     \
-          base::Histogram::kUmaTargetedHistogramFlag))
-
-#define UMA_HISTOGRAM_MEGABYTES_LINEAR(name, sample) \
-  UMA_HISTOGRAM_LINEAR(name, sample, 2500, 50)
-
-void RecordMemoryStats(RecordMemoryStatsType type) {
-  base::SystemMemoryInfoKB memory;
-  if (!base::GetSystemMemoryInfo(&memory))
-    return;
-#if defined(OS_CHROMEOS)
-  // Record graphics GEM object size in a histogram with 50 MB buckets.
-  int mem_graphics_gem_mb = 0;
-  if (memory.gem_size != -1)
-    mem_graphics_gem_mb = memory.gem_size / 1024 / 1024;
-
-  // Record shared memory (used by renderer/GPU buffers).
-  int mem_shmem_mb = memory.shmem / 1024;
-#endif
-
-  // On Intel, graphics objects are in anonymous pages, but on ARM they are
-  // not. For a total "allocated count" add in graphics pages on ARM.
-  int mem_allocated_mb = (memory.active_anon + memory.inactive_anon) / 1024;
-#if defined(OS_CHROMEOS) && defined(ARCH_CPU_ARM_FAMILY)
-  mem_allocated_mb += mem_graphics_gem_mb;
-#endif
-
-  int mem_available_mb =
-      (memory.active_file + memory.inactive_file + memory.free) / 1024;
-
-  switch (type) {
-    case RECORD_MEMORY_STATS_TAB_DISCARDED: {
-#if defined(OS_CHROMEOS)
-      UMA_HISTOGRAM_MEGABYTES_LINEAR("Tabs.Discard.MemGraphicsMB",
-                                     mem_graphics_gem_mb);
-      UMA_HISTOGRAM_MEGABYTES_LINEAR("Tabs.Discard.MemShmemMB", mem_shmem_mb);
-#endif
-      UMA_HISTOGRAM_ALLOCATED_MEGABYTES("Tabs.Discard.MemAllocatedMB",
-                                        mem_allocated_mb);
-      UMA_HISTOGRAM_LARGE_MEMORY_MB("Tabs.Discard.MemAvailableMB",
-                                    mem_available_mb);
-      break;
-    }
-    case RECORD_MEMORY_STATS_CONTENTS_OOM_KILLED: {
-#if defined(OS_CHROMEOS)
-      UMA_HISTOGRAM_MEGABYTES_LINEAR("Memory.OOMKill.Contents.MemGraphicsMB",
-                                     mem_graphics_gem_mb);
-      UMA_HISTOGRAM_MEGABYTES_LINEAR("Memory.OOMKill.Contents.MemShmemMB",
-                                     mem_shmem_mb);
-#endif
-      UMA_HISTOGRAM_ALLOCATED_MEGABYTES(
-          "Memory.OOMKill.Contents.MemAllocatedMB", mem_allocated_mb);
-      UMA_HISTOGRAM_LARGE_MEMORY_MB("Memory.OOMKill.Contents.MemAvailableMB",
-                                    mem_available_mb);
-      break;
-    }
-    case RECORD_MEMORY_STATS_EXTENSIONS_OOM_KILLED: {
-#if defined(OS_CHROMEOS)
-      UMA_HISTOGRAM_MEGABYTES_LINEAR("Memory.OOMKill.Extensions.MemGraphicsMB",
-                                     mem_graphics_gem_mb);
-      UMA_HISTOGRAM_MEGABYTES_LINEAR("Memory.OOMKill.Extensions.MemShmemMB",
-                                     mem_shmem_mb);
-#endif
-      UMA_HISTOGRAM_ALLOCATED_MEGABYTES(
-          "Memory.OOMKill.Extensions.MemAllocatedMB", mem_allocated_mb);
-      UMA_HISTOGRAM_LARGE_MEMORY_MB("Memory.OOMKill.Extensions.MemAvailableMB",
-                                    mem_available_mb);
-      break;
-    }
-  }
-}
-
-}  // namespace memory