Update from https://crrev.com/329939

base/sys_info.cc

 // Copyright (c) 2012 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/sys_info.h"
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
+#include "base/metrics/field_trial.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
 #include "base/sys_info_internal.h"
 #include "base/time/time.h"
 
 namespace base {
 
 #if !defined(OS_ANDROID)
 
 static const int kLowMemoryDeviceThresholdMB = 512;
 
 bool DetectLowEndDevice() {
   CommandLine* command_line = CommandLine::ForCurrentProcess();
   if (command_line->HasSwitch(switches::kEnableLowEndDeviceMode))
     return true;
   if (command_line->HasSwitch(switches::kDisableLowEndDeviceMode))
     return false;
 
   int ram_size_mb = SysInfo::AmountOfPhysicalMemoryMB();
   return (ram_size_mb > 0 && ram_size_mb < kLowMemoryDeviceThresholdMB);
 }
 
 static LazyInstance<
   internal::LazySysInfoValue<bool, DetectLowEndDevice> >::Leaky
   g_lazy_low_end_device = LAZY_INSTANCE_INITIALIZER;
 
 // static
 bool SysInfo::IsLowEndDevice() {
+  const std::string group_name =
+      base::FieldTrialList::FindFullName("MemoryReduction");
+
+  // Low End Device Mode will be enabled if this client is assigned to
+  // one of those EnabledXXX groups.
+  if (StartsWithASCII(group_name, "Enabled", true))
+    return true;
+
   return g_lazy_low_end_device.Get().value();
 }
 #endif
 
 #if !defined(OS_MACOSX) || defined(OS_IOS)
 std::string SysInfo::HardwareModelName() {
   return std::string();
 }
 #endif
 
 // static
 int64 SysInfo::Uptime() {
   // This code relies on an implementation detail of TimeTicks::Now() - that
   // its return value happens to coincide with the system uptime value in
   // microseconds, on Win/Mac/iOS/Linux/ChromeOS and Android.
   int64 uptime_in_microseconds = TimeTicks::Now().ToInternalValue();
   return uptime_in_microseconds / 1000;
 }
 
 }  // namespace base