Allow tab model to be selected during merge if current model has no tabs

chrome/android/java/src/org/chromium/chrome/browser/tabmodel/TabPersistentStore.java

Index: chrome/android/java/src/org/chromium/chrome/browser/tabmodel/TabPersistentStore.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/tabmodel/TabPersistentStore.java b/chrome/android/java/src/org/chromium/chrome/browser/tabmodel/TabPersistentStore.java
index 1bfbef6313b1ea72abd98f771805c0f4a5b2f0ba..75e389abe37ce801ecade9a01ac39835fa98c2a5 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/tabmodel/TabPersistentStore.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/tabmodel/TabPersistentStore.java
@@ -614,13 +614,18 @@ public class TabPersistentStore extends TabPersister {
         // was selected in the other model before the merge should be selected after the merge.
         if (setAsActive || (tabToRestore.fromMerge && restoredIndex == 0)) {
             boolean wasIncognitoTabModelSelected = mTabModelSelector.isIncognitoSelected();
+            int selectedModelTabCount = mTabModelSelector.getCurrentModel().getCount();
+
             TabModelUtils.setIndex(model, TabModelUtils.getTabIndexById(model, tabId));
             boolean isIncognitoTabModelSelected = mTabModelSelector.isIncognitoSelected();
 
             // Setting the index will cause the tab's model to be selected. Set it back to the model
-            // that was selected before setting the index if the index is being set during a merge.
+            // that was selected before setting the index if the index is being set during a merge
+            // unless the previously selected model is empty (e.g. showing the empty background
+            // view on tablets).
             if (tabToRestore.fromMerge
-                    && wasIncognitoTabModelSelected != isIncognitoTabModelSelected) {
+                    && wasIncognitoTabModelSelected != isIncognitoTabModelSelected
+                    && selectedModelTabCount != 0) {
                 mTabModelSelector.selectModel(wasIncognitoTabModelSelected);
             }
         }