[Editing][Codehealth] Rewrite user-select-all-selection.html with assert_selection.

third_party/WebKit/LayoutTests/editing/assert_selection.html

Index: third_party/WebKit/LayoutTests/editing/assert_selection.html
diff --git a/third_party/WebKit/LayoutTests/editing/assert_selection.html b/third_party/WebKit/LayoutTests/editing/assert_selection.html
index a93a430c412b360913fb373fbae48966caa4eb2c..4cb9b6aef588f8f473f79a92e22add7d0e3550e6 100644
--- a/third_party/WebKit/LayoutTests/editing/assert_selection.html
+++ b/third_party/WebKit/LayoutTests/editing/assert_selection.html
@@ -61,11 +61,6 @@ test(() => {
 }, 'markers around table');
 
 test(() => {
-    assert_equals(checked_assert_selection('foo', 'noop', 'baz'),
-        'You should specify caret position in "foo".');
-}, 'no marker in input');
-
-test(() => {
     assert_equals(checked_assert_selection('fo|o', 'noop', 'fo|o'),
         'no exception');
 }, 'no marker in output');