[test] Fix lib/mirrors/library_uri_io_test to pass when running not from source

This test was assuming that Platform.script would be equal to library
URI, but this is not the case when running from a dill file or a
snapshot.

Change-Id: I0ff2249b5b5301d6463ceca48097df7cb64e78b9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/167501
Reviewed-by: RĂ©gis Crelier <regis@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
diff --git a/tests/lib/mirrors/library_uri_io_test.dart b/tests/lib/mirrors/library_uri_io_test.dart
index 8400843..302e848 100644
--- a/tests/lib/mirrors/library_uri_io_test.dart
+++ b/tests/lib/mirrors/library_uri_io_test.dart
@@ -23,6 +23,11 @@
 main() {
   var mirrors = currentMirrorSystem();
   test("Test current library uri", () {
+    if (!Platform.script.toString().endsWith('.dart')) {
+      print("Skipping library uri test as not running from source "
+          "(Platform.script = ${Platform.script})");
+      return;
+    }
     Uri uri = Uri.base.resolveUri(Platform.script);
     testLibraryUri(new Class(), uri);
   });
diff --git a/tests/lib_2/mirrors/library_uri_io_test.dart b/tests/lib_2/mirrors/library_uri_io_test.dart
index 8400843..302e848 100644
--- a/tests/lib_2/mirrors/library_uri_io_test.dart
+++ b/tests/lib_2/mirrors/library_uri_io_test.dart
@@ -23,6 +23,11 @@
 main() {
   var mirrors = currentMirrorSystem();
   test("Test current library uri", () {
+    if (!Platform.script.toString().endsWith('.dart')) {
+      print("Skipping library uri test as not running from source "
+          "(Platform.script = ${Platform.script})");
+      return;
+    }
     Uri uri = Uri.base.resolveUri(Platform.script);
     testLibraryUri(new Class(), uri);
   });