Leave from the current root when the root is removed.

This is needed to handle removable roots.

1. Add a listener to RootCache.
2. BaseActivity handles roots change and leaves from the current
   directory if the current root is removed.

BUG=26316940
Change-Id: I41921fe17782fa1a2d9e58f55ea84326b8f1d3c0
2 files changed
tree: 57da39565a5ae04dff2b3c4957fdf188e29972be
  1. res/
  2. src/
  3. tests/
  4. Android.mk
  5. AndroidManifest.xml
  6. wrap_alpha.py