#2529. Fix failing API core tests (#2533)

LibTest/core/DateTime/parse_A01_t03.dart

@@ -19,7 +19,9 @@ check(String str, int year, int month, int day, int hours, int minutes,
   Expect.equals(minutes, d.minute);
   Expect.equals(seconds, d.second);
   Expect.equals(milliseconds, d.millisecond);
-  Expect.equals(microseconds, d.microsecond);
+  if (!isJS) { // microseconds are not supported on Web
+    Expect.equals(microseconds, d.microsecond);
+  }
 }
 
 main() {

LibTest/core/StackOverflowError/stackTrace_A01_t01.dart

@@ -3,7 +3,8 @@
 // BSD-style license that can be found in the LICENSE file.
 
 /// @assertion StackTrace stackTrace
-/// @description Checks that this property is not null if error is thrown
+/// @description Checks that this property is not null for the newly created
+/// instance
 /// @author [email protected]
 /// @issue 28179
 
@@ -12,9 +13,4 @@ import "../../../Utils/expect.dart";
 main() {
   Error e = new StackOverflowError();
   Expect.isNull(e.stackTrace);
-  try {
-    throw e;
-  } on StackOverflowError catch (er) {
-    Expect.isNotNull(e.stackTrace);
-  }
 }

LibTest/core/Uri/Uri.dataFromBytes_A01_t02.dart

@@ -51,6 +51,6 @@ main() {
   check(l, "image/gif");
   check(l, "text/plain");
   check(l, "Text/Plain");
-  check(l, "Avada / Kedavra");
-  check(l, "Абра / Кадабра");
+  check(l, "avada / kedavra");
+  check(l, "абра / кадабра");
 }

LibTest/core/UriData/UriData.fromBytes_A01_t02.dart

@@ -34,6 +34,6 @@ main() {
   check(l, "image/gif");
   check(l, "text/plain");
   check(l, "Text/Plain");
-  check(l, "Avada / Kedavra");
-  check(l, "Абра / Кадабра");
+  check(l, "avada / kedavra");
+  check(l, "абра / кадабра");
 }