Merge "Widgets tray should preserve scroll position during screen rotation" into ub-launcher3-calgary

src/com/android/launcher3/Launcher.java

@@ -1956,9 +1956,6 @@ public class Launcher extends Activity
             outState.putInt(RUNTIME_STATE_PENDING_ADD_WIDGET_ID, mPendingAddWidgetId);
         }
 
-        // Save the current widgets tray?
-        // TODO(hyunyoungs)
-
         if (mLauncherCallbacks != null) {
             mLauncherCallbacks.onSaveInstanceState(outState);
         }

src/com/android/launcher3/widget/WidgetsRecyclerView.java

@@ -23,7 +23,6 @@ import android.support.v7.widget.LinearLayoutManager;
 import android.util.AttributeSet;
 import android.view.View;
 import com.android.launcher3.BaseRecyclerView;
-import com.android.launcher3.R;
 import com.android.launcher3.model.PackageItemInfo;
 import com.android.launcher3.model.WidgetsModel;
 
@@ -58,6 +57,9 @@ public class WidgetsRecyclerView extends BaseRecyclerView {
     protected void onFinishInflate() {
         super.onFinishInflate();
         addOnItemTouchListener(this);
+        // create a layout manager with Launcher's context so that scroll position
+        // can be preserved during screen rotation.
+        setLayoutManager(new LinearLayoutManager(getContext()));
     }
 
     public int getFastScrollerTrackColor(int defaultTrackColor) {