Create a skeleton updater main for Windows.

This change builds an executable program on Windows, which returns
a hardcoded value. The value is tested by a unit test.

The updater executable contains a valid resource file and manifest.

An upcoming change will hook the test with the test bots.
Then, another change will implement a similar function for macOS.

Bug: 925489
Change-Id: Id97f4740a2cd9e3d21c00e631a8e03c19757468a
Reviewed-on: https://chromium-review.googlesource.com/c/1437266
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Joshua Pawlicki <waffles@chromium.org>
Commit-Queue: Sorin Jianu <sorin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#627053}

• BUILD.gn[diff]
• chrome/test/BUILD.gn[diff]
• chrome/updater/BUILD.gn[Added - diff]
• chrome/updater/win/BUILD.gn[Added - diff]
• chrome/updater/win/main.cc[Added - diff]
• chrome/updater/win/updater.rc[Added - diff]
• chrome/updater/win/updater.ver[Added - diff]
• chrome/updater/win/updater_unittest.cc[Added - diff]