[Editing][CodeHealth] Allow assert_selection have no anchor sample text.

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..324ba8c79f372a3fe83079ab075a1f233253dbaf 100644
--- a/third_party/WebKit/LayoutTests/editing/assert_selection.html
+++ b/third_party/WebKit/LayoutTests/editing/assert_selection.html
@@ -14,6 +14,7 @@ function checked_assert_selection(input, command, output) {
 }
 
 test(() => {
+    assert_selection('foo', 'noop', 'foo');
     assert_selection('|foo', 'noop', '|foo');
     assert_selection('f|oo', 'noop', 'f|oo');
     assert_selection('foo|', 'noop', 'foo|');
@@ -61,11 +62,6 @@ 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');