Revive DeadZone

Override dispatchTouchEvent for the root FrameLayout
of NavigationBar to process ACTION_OUTSIDE MotionEvents
and dispatch directly to DeadZone to keep track of the
most recent outside tap.
Clarified documentation of ACTION_OUTSIDE behaviour.

Bug: 37552674
Test: open IME, tap any key, then quickly tap on top half
of the home button. The home button tap is ignored
and device does not go to homescreen.

Change-Id: Icb5cf6c76959f3514b8b94c09e38cc5434f31b23
diff --git a/tests/testables/src/android/testing/BaseFragmentTest.java b/tests/testables/src/android/testing/BaseFragmentTest.java
index 32ee091..f1e4d21 100644
--- a/tests/testables/src/android/testing/BaseFragmentTest.java
+++ b/tests/testables/src/android/testing/BaseFragmentTest.java
@@ -50,7 +50,7 @@
     private static final int VIEW_ID = 42;
     private final Class<? extends Fragment> mCls;
     private Handler mHandler;
-    private FrameLayout mView;
+    protected FrameLayout mView;
     protected FragmentController mFragments;
     protected Fragment mFragment;
 
@@ -61,9 +61,13 @@
         mCls = cls;
     }
 
+    protected void createRootView() {
+        mView = new FrameLayout(mContext);
+    }
+
     @Before
     public void setupFragment() throws Exception {
-        mView = new FrameLayout(mContext);
+        createRootView();
         mView.setId(VIEW_ID);
 
         assertNotNull("BaseFragmentTest must be tagged with @RunWithLooper",