Fix URLSearchParams to use the right encoding algorithm

third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/request.js

 if (self.importScripts) {
   importScripts('../resources/fetch-test-helpers.js');
 }
 
 var URL = 'https://www.example.com/test.html';
 
 test(function() {
     var headers = new Headers;
     headers.set('User-Agent', 'Mozilla/5.0');
     headers.set('Accept', 'text/html');
@@ skipping 630 matching lines @@
       .then(function() {
           var params = new URLSearchParams();
           params.append('sample string', '1234567890');
           request = new Request(URL, {method: 'POST', body: params});
           return request.text();
         })
       .then(function(result) {
           assert_equals(result, "sample+string=1234567890");
         })
       .then(function() {
+          // Alphanumeric characters and *-._ shouldn't be percent-encoded.
+          // The others must.
+          var params = new URLSearchParams();
+          params.append('\0\x1f!)*+,-./:?[^_{~\x7f\u0080',
+                        '\0\x1f!)*+,-./:?[^_{~\x7f\u0080');
+          request = new Request(URL, {method: 'POST', body: params});
+          return request.text();
+        })
+      .then(function(result) {
+          assert_equals(
+              result,
+              "%00%1F%21%29*%2B%2C-.%2F%3A%3F%5B%5E_%7B%7E%7F%C2%80=" +
+                  "%00%1F%21%29*%2B%2C-.%2F%3A%3F%5B%5E_%7B%7E%7F%C2%80");
+        })
+      .then(function() {
+          // CR and LF shouldn't be normalized into CRLF.
+          var params = new URLSearchParams();
+          params.append('\r \n \r\n', '\r \n \r\n');
+          request = new Request(URL, {method: 'POST', body: params});
+          return request.text();
+        })
+      .then(function(result) {
+          assert_equals(result, "%0D+%0A+%0D%0A=%0D+%0A+%0D%0A");
+        })
+      .then(function() {
           t.done();
         })
       .catch(unreached_rejection(t));
     assert_true(request.bodyUsed,
                 'bodyUsed must be true after calling text()');
   }, 'Request body test');
 
 test(function() {
     // https://fetch.spec.whatwg.org/#dom-request
     // Step 20:
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                            credentials: 'include',
                            body: 'this is a body'});
 
     return req.text()
         .then(t => {
            assert_equals(t, 'this is a body');
         });
   }, 'Credentials and body can both be set.');
 
 done();