Inline SuddenTermination.h into the one file that uses it.

There's no reason for all this ceremony now that we can depend on
public/platform directly.

R=eseidel@chromium.org, eseidel
BUG=297477

Review URL: https://codereview.chromium.org/25767002

git-svn-id: svn://svn.chromium.org/blink/trunk@158771 bbb929c8-8fbe-4397-9dbb-9b2b20218538