Breaking Change: merge BoringSSL branch into master

runtime/bin/net/README-updating

-# Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-# for details. All rights reserved. Use of this source code is governed by a
-# BSD-style license that can be found in the LICENSE file.
-
-The standalone Dart executable uses the NSS library from Mozilla to
-support secure networking connections (SSL and TLS).  It uses a copy
-of the library from the Chromium repository, that includes patches
-added by Chromium.  We pin this to a fixed revision, using the
-nss_revision variable in all the DEPS files in the deps directory of
-the Dart repository.
-
-This revision should be updated when new security fixes are added to
-NSS, or every few months.  The .gyp files in this directory are copies
-of the .gyp files in the Chromium copy of NSS, with changes made to
-account for the configurations and directory structure of the Dart
-repository.  Differences between the Chromium versions and the Dart
-versions should be annotated with "# Added by Dart'.
-
-All the files should have a comment saying where the original file is
-in the Chromium repository. To update these files, look at the diff
-between the two revisions in Chromium, and apply the changes manually,
-with any needed modifications, to the Dart copies.  Our aim is to keep
-the difference between the Chromium and Dart copies as small as
-possible.
-
-The nss_memio.cc and nss_memio.h files are also taken from Chromium,
-and should be updated at the same time.  The os_Linux.s file is new,
-and should not need changing.
-
-The file nss.gyp includes support for disabling compilation of NSS
-using the variable dart_io_support, when building configurations that
-don't use it.  NSS compilation is disabled when building Dartium,
-because Chromium includes its own copy, and the build process would
-get confused.