Add new native Looper API.

This allows us to avoid exposing the file descriptor of
the event queue; instead, you attach an event queue to
a looper.  This will also should allow native apps to be
written without the need for a separate thread, by attaching
the event queue to the main thread's looper and scheduling
their own messages there.

Change-Id: I38489282635895ae2cbfacb88599c1b1cad9b239
diff --git a/native/android/Android.mk b/native/android/Android.mk
index fe8ed00..376c64f 100644
--- a/native/android/Android.mk
+++ b/native/android/Android.mk
@@ -8,6 +8,7 @@
 LOCAL_SRC_FILES:= \
     activity.cpp \
     input.cpp \
+    looper.cpp \
     native_window.cpp
 
 LOCAL_SHARED_LIBRARIES := \