Fix an assertion failure in FrameSelection::selectAll().

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/editing/FrameSelection.h"
 
 #include "bindings/core/v8/ExceptionStatePlaceholder.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/Text.h"
@@ skipping 196 matching lines @@
     EXPECT_EQ(Position::beforeNode(bottom->parentNode()), visibleSelectionInDOMTree().extent());
     EXPECT_EQ(Position(bottom, 0), visibleSelectionInDOMTree().start());
     EXPECT_EQ(Position(bottom, 3), visibleSelectionInDOMTree().end());
 
     EXPECT_EQ(PositionInComposedTree(bottom, 3), visibleSelectionInComposedTree().base());
     EXPECT_EQ(PositionInComposedTree(top, 1), visibleSelectionInComposedTree().extent());
     EXPECT_EQ(PositionInComposedTree(top, 1), visibleSelectionInComposedTree().start());
     EXPECT_EQ(PositionInComposedTree(bottom, 3), visibleSelectionInComposedTree().end());
 }
 
+TEST_F(FrameSelectionTest, SelectAllWithUnselectableRoot)
+{
+    RefPtrWillBeRawPtr<Element> select = document().createElement("select", ASSERT_NO_EXCEPTION);
+    document().replaceChild(select.get(), document().documentElement());
+    selection().selectAll();
+    EXPECT_TRUE(selection().isNone()) << "Nothing should be selected if the content of the documentElement is not selctable.";
+}
+
 } // namespace blink