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/libs/ui/InputManager.cpp b/libs/ui/InputManager.cpp
index 32c58b4..e1d15a4 100644
--- a/libs/ui/InputManager.cpp
+++ b/libs/ui/InputManager.cpp
@@ -85,6 +85,10 @@
     return mDispatcher->injectInputEvent(event, injectorPid, injectorUid, sync, timeoutMillis);
 }
 
+void InputManager::preemptInputDispatch() {
+    mDispatcher->preemptInputDispatch();
+}
+
 void InputManager::getInputConfiguration(InputConfiguration* outConfiguration) const {
     mReader->getCurrentInputConfiguration(outConfiguration);
 }