Hook up more GN toolkit and UI-based flags.

This renames the hack "my_msvs" project to "feature_flags" and creates an include file that gives the proper definitions of most of the UI-related feature and OS flags. Hook these flags up the build.

Review URL: https://codereview.chromium.org/160143002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250692 0039d316-1c4b-4281-b951-d872f2087c98
Mojo: Add API stubs for shared memory.

(Nothing actually implemented yet.)

R=darin@chromium.org

Review URL: https://codereview.chromium.org/148293017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250693 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250693
Enable net log.

BUG=None
TEST=launch app_shell with flag "--log-net-log=/path/to/net_log_file"

Review URL: https://codereview.chromium.org/138793006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250694 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250694