1. The granularities for traversing the text content of an accessibility
node info are now predefined constants and custom ones will not be
supported. This is the simplest solution - we can always add namespaced
user defined ones (unlikely).
2. Added actions for traversing web content. These actions can be used by
an accessibility service to transparently drive the JavaScript based
screen reader that is used for handling web content.
3. Added a new accessibility event type for traversing the content of a
view. This event is needed to announce to the user what is the next
element, i.e. the one next to the cursor, after the view's text was
traversed.
bug:5932640
bug:6389591
Change-Id: I144647da55bc4005c64f89865ef333af8359e145
b7ff3255c6