Text traversal at various granularities.

1. Implementing text content navigation at various granularities.
   For views that have content description but no text the
   content description is the traversed at character and word
   granularities. For views that inherit from TextView the
   supported granularities are character, word, line, and page.


Change-Id: I6640c24b0f588ce35b5cd901cfc513faa1849eb9
10 files changed