Add support for the PointerLocation overlay.

This change involves adding a new method to IWindowManager,
monitorInput() that returns an InputChannel to receive a copy of all
input that is dispatched to applications.  The caller must have
the READ_INPUT_STATE permission to make this request (similar to
other window manager methods such as getKeycodeState).

Change-Id: Icd14d810174a5b2928671ef16de73af88302aea0
diff --git a/core/java/android/view/IWindowManager.aidl b/core/java/android/view/IWindowManager.aidl
index d6b9212..e86e3bf 100644
--- a/core/java/android/view/IWindowManager.aidl
+++ b/core/java/android/view/IWindowManager.aidl
@@ -28,6 +28,7 @@
 import android.view.KeyEvent;
 import android.view.InputEvent;
 import android.view.MotionEvent;
+import android.view.InputChannel;
 
 /**
  * System private interface to the window manager.
@@ -119,6 +120,7 @@
     int getKeycodeStateForDevice(int devid, int sw);
     int getTrackballKeycodeState(int sw);
     int getDPadKeycodeState(int sw);
+    InputChannel monitorInput(String inputChannelName);
     
     // Report whether the hardware supports the given keys; returns true if successful
     boolean hasKeys(in int[] keycodes, inout boolean[] keyExists);