[Android] Fix a bug that snackbar does not show when there is no tab on tablet

chrome/android/java/src/org/chromium/chrome/browser/widget/emptybackground/EmptyBackgroundViewWrapper.java

Index: chrome/android/java/src/org/chromium/chrome/browser/widget/emptybackground/EmptyBackgroundViewWrapper.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/widget/emptybackground/EmptyBackgroundViewWrapper.java b/chrome/android/java/src/org/chromium/chrome/browser/widget/emptybackground/EmptyBackgroundViewWrapper.java
index c3cd962f71b984771f82327c6dc85f90af194811..fe230ffbb8bd3132314dfcd1365533bf8fc84588 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/widget/emptybackground/EmptyBackgroundViewWrapper.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/widget/emptybackground/EmptyBackgroundViewWrapper.java
@@ -12,6 +12,7 @@ import android.view.ViewStub;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.appmenu.AppMenuHandler;
 import org.chromium.chrome.browser.compositor.layouts.OverviewModeBehavior;
+import org.chromium.chrome.browser.snackbar.SnackbarManager;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.tabmodel.EmptyTabModelObserver;
 import org.chromium.chrome.browser.tabmodel.EmptyTabModelSelectorObserver;
@@ -34,6 +35,7 @@ public class EmptyBackgroundViewWrapper {
     private final TabModelObserver mTabModelObserver;
     private final TabModelSelectorObserver mTabModelSelectorObserver;
     private final OverviewModeBehavior mOverviewModeBehavior;
+    private final SnackbarManager mSnackbarManager;
 
     private EmptyBackgroundViewTablet mBackgroundView;
     private final AppMenuHandler mMenuHandler;
@@ -46,16 +48,19 @@ public class EmptyBackgroundViewWrapper {
      * @param activity             An {@link Activity} that represents a parent of the
      *                             {@link android.view.ViewStub}.
      * @param menuHandler          A {@link AppMenuHandler} to handle menu touch events.
+     * @param snackbarManager      The {@link SnackbarManager} to show the undo snackbar when the
+     *                             empty background is visible.
      * @param overviewModeBehavior A {@link OverviewModeBehavior} instance to detect when the app
      *                             is in overview mode.
      */
     public EmptyBackgroundViewWrapper(TabModelSelector selector, TabCreator tabCreator,
-            Activity activity, AppMenuHandler menuHandler,
+            Activity activity, AppMenuHandler menuHandler, SnackbarManager snackbarManager,
             OverviewModeBehavior overviewModeBehavior) {
         mActivity = activity;
         mMenuHandler = menuHandler;
         mTabModelSelector = selector;
         mTabCreator = tabCreator;
+        mSnackbarManager = snackbarManager;
         mOverviewModeBehavior = overviewModeBehavior;
         mTabModelObserver = new EmptyTabModelObserver() {
             @Override
@@ -142,6 +147,7 @@ public class EmptyBackgroundViewWrapper {
 
         if (mBackgroundView != null) {
             mBackgroundView.setEmptyContainerState(showEmptyBackground);
+            mSnackbarManager.overrideParent(showEmptyBackground ? mBackgroundView : null);
         }
     }