Simplify deleted hash table logic in FontPlatformDataChromiumWin.

BUG=

Review URL: https://chromiumcodereview.appspot.com/19540016

git-svn-id: svn://svn.chromium.org/blink/trunk@155031 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Re-land: Ensure that ArrayBuffers actively being used by the Web Audio API cannot be neutered

reland 19019002 which was reviewed by kbr@chromium.org

TBR=crogers@google.com

Review URL: https://chromiumcodereview.appspot.com/20804003

git-svn-id: svn://svn.chromium.org/blink/trunk@155032 bbb929c8-8fbe-4397-9dbb-9b2b20218538