Remove some dead NPAPI code after r363119.

The motivation is to remove longs in IPC messages, since they're not safe to send between 32 and 64 bit processes. Although these specific messages weren't used on Android, they block us from having checks against this.

BUG=493212,581409

Review URL: https://codereview.chromium.org/1662013002

Cr-Commit-Position: refs/heads/master@{#373369}
13 files changed