Revert of Add support for backgrounding processes on the Mac

base/process/process_mac.cc

Index: base/process/process_mac.cc
diff --git a/base/process/process_mac.cc b/base/process/process_mac.cc
deleted file mode 100644
index 4dc1806ccd27eed3f8ea480f1f09fe9708bd6ff5..0000000000000000000000000000000000000000
--- a/base/process/process_mac.cc
+++ /dev/null
@@ -1,126 +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 "base/process/process.h"
-
-#include "base/mac/mac_util.h"
-#include "base/mac/mach_logging.h"
-
-#include <mach/mach.h>
-
-// The following was added to <mach/task_policy.h> after 10.8.
-// TODO(shrike): Remove the TASK_OVERRIDE_QOS_POLICY ifndef once builders
-// reach 10.9 or higher.
-#ifndef TASK_OVERRIDE_QOS_POLICY
-
-#define TASK_OVERRIDE_QOS_POLICY 9
-
-typedef struct task_category_policy task_category_policy_data_t;
-typedef struct task_category_policy* task_category_policy_t;
-
-enum task_latency_qos {
-  LATENCY_QOS_TIER_UNSPECIFIED = 0x0,
-  LATENCY_QOS_TIER_0 = ((0xFF << 16) | 1),
-  LATENCY_QOS_TIER_1 = ((0xFF << 16) | 2),
-  LATENCY_QOS_TIER_2 = ((0xFF << 16) | 3),
-  LATENCY_QOS_TIER_3 = ((0xFF << 16) | 4),
-  LATENCY_QOS_TIER_4 = ((0xFF << 16) | 5),
-  LATENCY_QOS_TIER_5 = ((0xFF << 16) | 6)
-};
-typedef integer_t task_latency_qos_t;
-enum task_throughput_qos {
-  THROUGHPUT_QOS_TIER_UNSPECIFIED = 0x0,
-  THROUGHPUT_QOS_TIER_0 = ((0xFE << 16) | 1),
-  THROUGHPUT_QOS_TIER_1 = ((0xFE << 16) | 2),
-  THROUGHPUT_QOS_TIER_2 = ((0xFE << 16) | 3),
-  THROUGHPUT_QOS_TIER_3 = ((0xFE << 16) | 4),
-  THROUGHPUT_QOS_TIER_4 = ((0xFE << 16) | 5),
-  THROUGHPUT_QOS_TIER_5 = ((0xFE << 16) | 6),
-};
-
-#define LATENCY_QOS_LAUNCH_DEFAULT_TIER LATENCY_QOS_TIER_3
-#define THROUGHPUT_QOS_LAUNCH_DEFAULT_TIER THROUGHPUT_QOS_TIER_3
-
-typedef integer_t task_throughput_qos_t;
-
-struct task_qos_policy {
-  task_latency_qos_t task_latency_qos_tier;
-  task_throughput_qos_t task_throughput_qos_tier;
-};
-
-typedef struct task_qos_policy* task_qos_policy_t;
-#define TASK_QOS_POLICY_COUNT \
-  ((mach_msg_type_number_t)(sizeof(struct task_qos_policy) / sizeof(integer_t)))
-
-#endif  // TASK_OVERRIDE_QOS_POLICY
-
-namespace base {
-
-bool Process::CanBackgroundProcesses() {
-  return true;
-}
-
-bool Process::IsProcessBackgrounded(mach_port_t task_port) const {
-  // See SetProcessBackgrounded().
-  DCHECK(IsValid());
-  DCHECK_NE(task_port, TASK_NULL);
-
-  task_category_policy_data_t category_policy;
-  mach_msg_type_number_t task_info_count = TASK_CATEGORY_POLICY_COUNT;
-  boolean_t get_default = FALSE;
-
-  kern_return_t result =
-      task_policy_get(task_port, TASK_CATEGORY_POLICY,
-                      reinterpret_cast<task_policy_t>(&category_policy),
-                      &task_info_count, &get_default);
-  MACH_LOG_IF(ERROR, result != KERN_SUCCESS, result) <<
-      "task_policy_get TASK_CATEGORY_POLICY";
-
-  if (result == KERN_SUCCESS && get_default == FALSE) {
-    return category_policy.role == TASK_BACKGROUND_APPLICATION;
-  }
-  return false;
-}
-
-bool Process::SetProcessBackgrounded(mach_port_t task_port, bool background) {
-  DCHECK(IsValid());
-  DCHECK_NE(task_port, TASK_NULL);
-
-  if (!CanBackgroundProcesses()) {
-    return false;
-  }
-
-  task_category_policy category_policy;
-  category_policy.role =
-      background ? TASK_BACKGROUND_APPLICATION : TASK_FOREGROUND_APPLICATION;
-  kern_return_t result =
-      task_policy_set(task_port, TASK_CATEGORY_POLICY,
-                      reinterpret_cast<task_policy_t>(&category_policy),
-                      TASK_CATEGORY_POLICY_COUNT);
-
-  if (result != KERN_SUCCESS) {
-    MACH_LOG(ERROR, result) << "task_policy_set TASK_CATEGORY_POLICY";
-    return false;
-  } else if (!mac::IsOSMavericksOrLater()) {
-    return true;
-  }
-
-  // Latency QoS regulates timer throttling/accuracy. Select default tier
-  // on foreground because precise timer firing isn't needed.
-  struct task_qos_policy qos_policy = {
-      background ? LATENCY_QOS_TIER_5 : LATENCY_QOS_LAUNCH_DEFAULT_TIER,
-      background ? THROUGHPUT_QOS_TIER_5 : THROUGHPUT_QOS_LAUNCH_DEFAULT_TIER
-  };
-  result = task_policy_set(task_port, TASK_OVERRIDE_QOS_POLICY,
-                           reinterpret_cast<task_policy_t>(&qos_policy),
-                           TASK_QOS_POLICY_COUNT);
-  if (result != KERN_SUCCESS) {
-    MACH_LOG(ERROR, result) << "task_policy_set TASK_OVERRIDE_QOS_POLICY";
-    return false;
-  }
-
-  return true;
-}
-
-}  // namespace base