Back button should be able to close apps

sky/services/intents/src/org/domokit/intents/ActivityManagerImpl.java

Index: sky/services/intents/src/org/domokit/intents/ActivityManagerImpl.java
diff --git a/sky/services/intents/src/org/domokit/intents/ActivityManagerImpl.java b/sky/services/intents/src/org/domokit/intents/ActivityManagerImpl.java
index a59bc41722cb6e5398a6329a6fbf082de406c3a2..049d0eb5fdf2a56a0e2089f43e38e8792834e94f 100644
--- a/sky/services/intents/src/org/domokit/intents/ActivityManagerImpl.java
+++ b/sky/services/intents/src/org/domokit/intents/ActivityManagerImpl.java
@@ -4,6 +4,7 @@
 
 package org.domokit.intents;
 
+import android.app.Activity;
 import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.net.Uri;
@@ -20,12 +21,17 @@ import org.chromium.mojom.intents.StringExtra;
  */
 public class ActivityManagerImpl implements ActivityManager {
     private static final String TAG = "ActivityManagerImpl";
+    private static Activity sCurrentActivity;
     private Context mContext;
 
     public ActivityManagerImpl(Context context) {
         mContext = context;
     }
 
+    public static void setCurrentActivity(Activity activity) {
+        sCurrentActivity = activity;
+    }
+
     @Override
     public void close() {}
 
@@ -58,4 +64,13 @@ public class ActivityManagerImpl implements ActivityManager {
             Log.e(TAG, "Unable to startActivity", e);
         }
     }
+
+    @Override
+    public void finishCurrentActivity() {
+        if (sCurrentActivity != null) {
+            sCurrentActivity.finish();
+        } else {
+            Log.e(TAG, "Unable to finishCurrentActivity");
+        }
+    }
 }