Fix NPE on Activity start in TextView

Bug 6065279

The selection can be created programatically, and mEditor may be null
when it happens.

Make sure mEditor is created to display the selection highlight.

Change-Id: Idd66a5fd4ad327f9b390b539574e6878c794ba4a

Author: Gilles Debunne

core/java/android/widget/TextView.java

@@ -2980,8 +2980,7 @@ public void onRestoreInstanceState(Parcelable state) {
                           "/" + ss.selEnd + " out of range for " + restored +
                           "text " + mText);
                 } else {
-                    Selection.setSelection((Spannable) mText, ss.selStart,
-                                           ss.selEnd);
+                    Selection.setSelection((Spannable) mText, ss.selStart, ss.selEnd);
 
                     if (ss.frozenWithFocus) {
                         createEditorIfNeeded("restore instance with focus");
@@ -6983,6 +6982,9 @@ protected void onTextChanged(CharSequence text, int start, int lengthBefore, int
      */
     protected void onSelectionChanged(int selStart, int selEnd) {
         sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_TEXT_SELECTION_CHANGED);
+        // mEditor may be null if selection is created programatically.
+        createEditorIfNeeded("onSelectionChanged");
+        // Invalidate even when selection range is empty, to remove previous highlight
         getEditor().mTextDisplayListIsValid = false;
     }