The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cc8319b4398e1568d6ea270f74f4fa0146cd455c

commit cc8319b4398e1568d6ea270f74f4fa0146cd455c
Author: lawrencewu <lawrencewu@chromium.org>
Date: Fri Nov 18 19:34:23 2016

Refactor field_trial.cc

This change does three things:
1) removes the <handle>,<length> switch on the command line on Windows, since
   we are now using a static size.
2) creates CreateTrialsFromWindowsHandle(), which CreateTrialsFromCommandLine()
   will call, and makes CreateTrialsFromCommandLine more symmetric. We will probably
   do something similar for linux and mac
3) typedefs SharedPersistentMemoryAllocator::Reference and SharedPersistentMemoryAllocator
   to FieldTrial::FieldTrialRef and FieldTrialList::FieldTrialAllocator respectively.

BUG= 665247 

Review-Url: https://codereview.chromium.org/2501283002
Cr-Commit-Position: refs/heads/master@{#433264}

[modify] https://crrev.com/cc8319b4398e1568d6ea270f74f4fa0146cd455c/base/metrics/field_trial.cc
[modify] https://crrev.com/cc8319b4398e1568d6ea270f74f4fa0146cd455c/base/metrics/field_trial.h