Cherry-pick: [Android WebView] Do not throttle if need picture listener

Cherry-pick of Chromium crrev.com/r229116

BUG: 11230312

Original description:

Currently as implemented, this will ensure clearView can be
unset even if AwContents.onPause is called.

Should considering refactoring clearView such that this case
can be dealt with more sanely.

Change-Id: Id5f160d339eace1b58d7fdc3666fc1a9f5248ead
1 file changed