Android: Delete ContentViewCore.isAlive

This CL deletes the API |ContentViewCore.isAlive| and lets the callsites
use |WebContents.isDestroyed| (after negation) instead.

!CVC.isAlive() and WebContents.isDestroyed() basically serve the same
purpose that indicate WebContents (and its associated objecs) are in
the destroyed state. Once they return true, no calls should be made
on WebContents.

WebContents now defines |mIsAlive| for the deleted api to be replaced
with !WebContents.isDestroyed(). It is set to false by CVC.destroy()
or native WebContentsAndroid dtor, whichever comes first, to indicate
that WebContents is on its way to destruction. (WebContents.destroy()
also leads to setting it to false by way of WebcontentsAndroid dtor).

Bug: 598880
Change-Id: I8aa864e4efdd5c326e62c284bbda5987dc0e60a5
Reviewed-by: Ted Choc <>
Reviewed-by: Bo <>
Commit-Queue: Jinsuk Kim <>
Cr-Commit-Position: refs/heads/master@{#561733}
8 files changed