Merge "Finish when browsed root goes away." into mnc-dev

packages/DocumentsUI/src/com/android/documentsui/BaseActivity.java

@@ -25,7 +25,6 @@ import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.List;
 import java.util.concurrent.Executor;
 
@@ -96,6 +95,22 @@ abstract class BaseActivity extends Activity {
         mSearchManager = new SearchManager();
     }
 
+    @Override
+    public void onResume() {
+        super.onResume();
+
+        final State state = getDisplayState();
+        final RootInfo root = getCurrentRoot();
+
+        // If we're browsing a specific root, and that root went away, then we
+        // have no reason to hang around
+        if (state.action == State.ACTION_BROWSE && root != null) {
+            if (mRoots.getRootBlocking(root.authority, root.rootId) == null) {
+                finish();
+            }
+        }
+    }
+
     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         boolean showMenu = super.onCreateOptionsMenu(menu);