android: Don't invalidate UI resources if context is lost

android: Don't invalidate UI resources if context is lost

This callback implies that the resources are gone (because LTH
was deleted). What ends up happening is that the resources get
deleted while LTH still tries to call GetBitmap() on them.

This still needs some working invalidation mechanism for Thumbnails,
which don't have a persistent Bitmap they return from GetBitmap().

BUG=406879
NOTRY=True
TBR=dtrainor@chromium.org

Review URL: https://codereview.chromium.org/543543002

Cr-Commit-Position: refs/heads/master@{#293252}
(cherry picked from commit f5186515e0607b24d77a0bca13634f0158865b8e)

Committed: https://chromium.googlesource.com/chromium/src/+/201c5eb067d67b2aa05436ce5ef616e42abec908

[no sievers, 2014-09-05 17:59:19]

Committed patchset #1 (id:1) manually as 201c5eb.