Added crashpad support for Windows

This mimics behavior with Mac and Linux, with --enable-crash-reporter
--crash-dumps-dir in headless_shell and chrome --headless

Note that browsertests cannot be enabled as they are since in Windows the crash handler
is forked from the Headless Shell.

BUG=686608

Review-Url: https://codereview.chromium.org/2835913002
Cr-Commit-Position: refs/heads/master@{#472017}
3 files changed