Implement DISALLOW_COPY_AND_ASSIGN using =delete for Linux only.

This lands the new implementation for only (non-CrOS) Linux.  Hopefully this
will prevent regressions in cross-platform code while other platforms are
brought up.

BUG=447156
TEST=none

Review-Url: https://codereview.chromium.org/2006733006
Cr-Commit-Position: refs/heads/master@{#396295}
1 file changed