Switch URL and URLUtils interfaces over to use ScalarValueString.

LayoutTests/fast/domurl/url-constructor.html

Index: LayoutTests/fast/domurl/url-constructor.html
diff --git a/LayoutTests/fast/domurl/url-constructor.html b/LayoutTests/fast/domurl/url-constructor.html
index 0205a12c3016bcaeed307e30334ac3eddb0b243a..0697a6ba77bd69e11454ef9d23b1ef374d903a33 100644
--- a/LayoutTests/fast/domurl/url-constructor.html
+++ b/LayoutTests/fast/domurl/url-constructor.html
@@ -14,6 +14,8 @@ function assertThrows(func, expected) {
     assert_true(false, 'Expected an exception with string: ' + expected);
 }
 
+var encodedReplacementCharacter = encodeURIComponent('\ufffd');

[arv (Not doing code reviews), 2014/06/23 16:12:01]

Since this is only used in one place, consider moving it closer to its usage.

[sof, 2014/06/23 19:02:48]

Certainly; moved it next to its use.

+
 test(function() {
     assert_equals(new URL('http://www.domain.com/a/b').toString(), 'http://www.domain.com/a/b');
     assert_equals(new URL('/c/d', 'http://www.domain.com/a/b').toString(), 'http://www.domain.com/c/d');
@@ -21,6 +23,9 @@ test(function() {
 
     var base = new URL('http://www.domain.com/a/b');
     assert_equals(new URL('b/c', base).toString(), 'http://www.domain.com/a/b/c');
+
+    // Unmatched surrogate handling
+    assert_equals(new URL('b/c', 'http://www.domain.com/\ud801/b').toString(), 'http://www.domain.com/' + encodedReplacementCharacter + '/b/c');
 }, 'Valid URLs');
 
 test(function() {