Convert Encoding API tests to W3C testharness.js

LayoutTests/fast/encoding/api/surrogate-pairs-expected.txt

-Test invalid UTF-16 surrogate pairs with UTF-8 encoding
+This is a testharness.js-based test.
+PASS Invalid surrogate pairs encoded into UTF-8: Sanity check 
+PASS Invalid surrogate pairs encoded into UTF-8: Surrogate half (low) 
+PASS Invalid surrogate pairs encoded into UTF-8: Surrogate half (high) 
+PASS Invalid surrogate pairs encoded into UTF-8: Surrogate half (low), in a string 
+PASS Invalid surrogate pairs encoded into UTF-8: Surrogate half (high), in a string 
+PASS Invalid surrogate pairs encoded into UTF-8: Wrong order 
+Harness: the test ran to completion.
 
-On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
-
-
-encoded = new TextEncoder('utf-8').encode('abc123')
-PASS JSON.stringify([].slice.call(encoded)) is "[97,98,99,49,50,51]"
-
-encoded = new TextEncoder('utf-8').encode('\ud800')
-PASS JSON.stringify([].slice.call(encoded)) is "[239,191,189]"
-
-encoded = new TextEncoder('utf-8').encode('\udc00')
-PASS JSON.stringify([].slice.call(encoded)) is "[239,191,189]"
-
-encoded = new TextEncoder('utf-8').encode('abc\ud800123')
-PASS JSON.stringify([].slice.call(encoded)) is "[97,98,99,239,191,189,49,50,51]"
-
-encoded = new TextEncoder('utf-8').encode('abc\udc00123')
-PASS JSON.stringify([].slice.call(encoded)) is "[97,98,99,239,191,189,49,50,51]"
-
-encoded = new TextEncoder('utf-8').encode('\udc00\ud800')
-PASS JSON.stringify([].slice.call(encoded)) is "[239,191,189,239,191,189]"
-
-PASS successfullyParsed is true
-
-TEST COMPLETE
-