Remove code from obsolete field trial from 2015.

Originally added here: https://codereview.chromium.org/1117193004

Bug: 799180
Change-Id: I8e46beafdc57c249fb9909e39c197519b2652c7b
Reviewed-on: https://chromium-review.googlesource.com/902769Reviewed-by: Mark Mentovai <mark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534776}

base/sys_info.cc

@@ -7,9 +7,6 @@
 #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"
 #include "build/build_config.h"
@@ -64,14 +61,6 @@ static LazyInstance<
 
 // 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 (StartsWith(group_name, "Enabled", CompareCase::SENSITIVE))
-    return true;
-
   return g_lazy_low_end_device.Get().value();
 }
 #endif