1. This patch takes care of the case where a magnified window is covering an unmagnigied
one. One example is a dialog that covers the IME window.
bug:7634430
2. Ensuring that the UI automator tool can connect and correctly dump the screen.
bug:7694696
3. Removed the partial implementation for multi display magnification. It adds
unnecessary complexity since it cannot be implemented without support for
input from multiple screens. We will revisit when necessary.
4. Moved the magnified border window as a surface in the window manager.
5. Moved the mediator APIs on the window manager and the policy methods on the
WindowManagerPolicy.
6. Implemented batch event processing for the accessibility input filter.
Change-Id: I4ebf68b94fb07201e124794f69611ece388ec116