Native input event dispatching.

Target identification is now fully native.
Fixed a couple of minor issues related to input injection.
Native input enabled by default, can be disabled by setting
WindowManagerPolicy.ENABLE_NATIVE_INPUT_DISPATCH to false.

Change-Id: I7edf66ed3e987cc9306ad4743ac57a116af452ff
diff --git a/include/ui/Input.h b/include/ui/Input.h
index 32f85b3..57b292b 100644
--- a/include/ui/Input.h
+++ b/include/ui/Input.h
@@ -87,6 +87,9 @@
     // Indicates that the screen was dim when the event was received and the event
     // should brighten the device.
     POLICY_FLAG_BRIGHT_HERE = 0x20000000,
+
+    // Indicates that the dispatcher should call back into the policy before dispatching. */
+    POLICY_FLAG_INTERCEPT_DISPATCH = 0x40000000,
 };
 
 /*