Make Editor::revealSelectionAfterEditingOperation check document availability

third_party/WebKit/Source/core/editing/Editor.cpp

Index: third_party/WebKit/Source/core/editing/Editor.cpp
diff --git a/third_party/WebKit/Source/core/editing/Editor.cpp b/third_party/WebKit/Source/core/editing/Editor.cpp
index 811144a416ed2cd759e9481cb96c5f0c51d9be2a..f9aaa29cb972442c5395b141ecbe744bf1c0bb5d 100644
--- a/third_party/WebKit/Source/core/editing/Editor.cpp
+++ b/third_party/WebKit/Source/core/editing/Editor.cpp
@@ -1304,6 +1304,8 @@ void Editor::revealSelectionAfterEditingOperation(
     RevealExtentOption revealExtentOption) {
   if (m_preventRevealSelection)
     return;
+  if (!frame().selection().isAvailable())
+    return;
   frame().selection().revealSelection(alignment, revealExtentOption);
 }