Fix document stack.

We need to add document to stack by using 'push' method instead of 'add'
method.

BUG=26437613

Change-Id: I3e4ac6b0d03cacbe2d6cdd93443ce1c96c8c47d9
2 files changed
tree: 4d3e044960e563ed6c3b75a8ba2b89f38efe35d6
  1. res/
  2. src/
  3. tests/
  4. Android.mk
  5. AndroidManifest.xml
  6. wrap_alpha.py