Log a warning when action bar view states cannot be restored.

Some apps can get into a case where the saved view hierarchy states
for action bar views are missing. Log a warning instead of crashing.

Bug 6510800

Change-Id: I95ede64ec584892e6e76ca9ab9d53e9d3689984f

Author: adamp

policy/src/com/android/internal/policy/impl/PhoneWindow.java

@@ -1630,7 +1630,12 @@ public void restoreHierarchyState(Bundle savedInstanceState) {
         if (mActionBar != null) {
             SparseArray<Parcelable> actionBarStates =
                     savedInstanceState.getSparseParcelableArray(ACTION_BAR_TAG);
-            mActionBar.restoreHierarchyState(actionBarStates);
+            if (actionBarStates != null) {
+                mActionBar.restoreHierarchyState(actionBarStates);
+            } else {
+                Log.w(TAG, "Missing saved instance states for action bar views! " +
+                        "State will not be restored.");
+            }
         }
     }