Address comments in ag/1514806.

* Isolate LinkedList and stack/root manipulation in DocumentStack
* Consolidate ProviderAccess into DocumentAccess
* Pass Uri as the the param to LoadDocStackTask
* Tidy up initLocation() in picker.Actionhandler
* Add a test case for initLocation with data in picking intents

Bug: 32156176
Change-Id: I3ca07342fc594e47fc003df146dcf982f152f56d
diff --git a/src/com/android/documentsui/NavigationViewManager.java b/src/com/android/documentsui/NavigationViewManager.java
index 4f97111..65f9000 100644
--- a/src/com/android/documentsui/NavigationViewManager.java
+++ b/src/com/android/documentsui/NavigationViewManager.java
@@ -75,7 +75,7 @@
         boolean changed = false;
         while (mState.stack.size() > position + 1) {
             changed = true;
-            mState.popDocument();
+            mState.stack.pop();
         }
         if (changed) {
             mEnv.refreshCurrentRootAndDirectory(AnimationView.ANIM_LEAVE);