tree 1cd193eabad10a7be9472c27fd6d0ce0a27f5534
parent ddb22d4e54afe67eab6f6bcfa9d95039158aa7ab
author George Mount <mount@google.com> 1479322392 -0800
committer George Mount <mount@google.com> 1483564422 -0800

Use safe access to OnPreDrawListener.

Bug 32472451

It is important to remove an OnPreDrawListener from the correct
ViewTreeObserver. When a View is added to the view hierarchy, the
initial ViewTreeObserver is not active. The listener must then be
removed from the current OnPreDrawListener. When a View has been
removed from the hierarchy, it is important to remove the listener
from the orignal ViewTreeObserver.

Test: gradlew connectedCheck in fragments/

Change-Id: I8ca2e7537542e5a3ba12273f9bd6897aca88dda0