[TabGroup] Only select tab when TabModel's index is valid

Change-Id: I1f47ae01c8bcde3693373538e050e8de4c3fcb4e
Bug: 985879
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1747379
Commit-Queue: Mei Liang <meiliang@chromium.org>
Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#688638}

chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_groups/TabGroupModelFilter.java

@@ -558,7 +558,11 @@ public class TabGroupModelFilter extends TabModelFilter {
         reorderGroup(TabGroup.INVALID_GROUP_ID);
 
         TabModel tabModel = getTabModel();
-        selectTab(tabModel.getTabAt(tabModel.index()));
+        if (tabModel.index() == TabModel.INVALID_TAB_INDEX) {
+            mCurrentGroupIndex = TabModel.INVALID_TAB_INDEX;
+        } else {
+            selectTab(tabModel.getTabAt(tabModel.index()));
+        }
 
         assert mGroupIdToGroupIndexMap.size() == mGroupIdToGroupMap.size();
     }
@@ -601,7 +605,11 @@ public class TabGroupModelFilter extends TabModelFilter {
         super.resetFilterState();
 
         TabModel tabModel = getTabModel();
-        selectTab(tabModel.getTabAt(tabModel.index()));
+        if (tabModel.index() == TabModel.INVALID_TAB_INDEX) {
+            mCurrentGroupIndex = TabModel.INVALID_TAB_INDEX;
+        } else {
+            selectTab(tabModel.getTabAt(tabModel.index()));
+        }
         mShouldRecordUma = true;
         mIsResetting = false;
     }