Fix tests that were broken in Chrome.

R=kevmoo@google.com

Review URL: https://codereview.chromium.org//1031063003

test/frontend/matcher/prints_test.dart

@@ -32,7 +32,7 @@ void main() {
         expectTestFailed(liveTest,
             "Expected: prints 'Goodbye, world!\\n'\n"
             "  ''\n"
-            "  Actual: <Closure: () => dynamic>\n"
+            "  Actual: <$closureString>\n"
             "   Which: printed 'Hello, world!\\n'\n"
             "  ''\n"
             "   Which: is different.\n"
@@ -49,7 +49,7 @@ void main() {
       }).then((liveTest) {
         expectTestFailed(liveTest,
             "Expected: prints contains 'Goodbye'\n"
-            "  Actual: <Closure: () => dynamic>\n"
+            "  Actual: <$closureString>\n"
             "   Which: printed 'Hello, world!\\n'\n"
             "  ''\n");
       });
@@ -61,7 +61,7 @@ void main() {
       }).then((liveTest) {
         expectTestFailed(liveTest,
             "Expected: prints contains 'Goodbye'\n"
-            "  Actual: <Closure: () => dynamic>\n"
+            "  Actual: <$closureString>\n"
             "   Which: printed nothing.\n");
       });
     });
@@ -103,7 +103,7 @@ void main() {
         expectTestFailed(liveTest, startsWith(
             "Expected: prints 'Goodbye, world!\\n'\n"
             "  ''\n"
-            "  Actual: <Closure: () => dynamic>\n"
+            "  Actual: <$closureString>\n"
             "   Which: printed 'Hello, world!\\n'\n"
             "  ''\n"
             "   Which: is different.\n"
@@ -121,7 +121,7 @@ void main() {
       }).then((liveTest) {
         expectTestFailed(liveTest, startsWith(
             "Expected: prints contains 'Goodbye'\n"
-            "  Actual: <Closure: () => dynamic>\n"
+            "  Actual: <$closureString>\n"
             "   Which: printed 'Hello, world!\\n'\n"
             "  ''"));
       });
@@ -133,7 +133,7 @@ void main() {
       }).then((liveTest) {
         expectTestFailed(liveTest, startsWith(
             "Expected: prints contains 'Goodbye'\n"
-            "  Actual: <Closure: () => dynamic>\n"
+            "  Actual: <$closureString>\n"
             "   Which: printed nothing."));
       });
     });

test/frontend/matcher/throws_test.dart

@@ -21,7 +21,7 @@ void main() {
         }).then((liveTest) {
           expectTestFailed(liveTest,
               "Expected: throws\n"
-              "  Actual: <Closure: () => dynamic>\n"
+              "  Actual: <$closureString>\n"
               "   Which: did not throw\n");
         });
       });
@@ -54,7 +54,7 @@ void main() {
         }).then((liveTest) {
           expectTestFailed(liveTest,
               "Expected: throws 'oh no'\n"
-              "  Actual: <Closure: () => dynamic>\n"
+              "  Actual: <$closureString>\n"
               "   Which: did not throw\n");
         });
       });
@@ -76,7 +76,7 @@ void main() {
         }).then((liveTest) {
           expectTestFailed(liveTest,
               "Expected: throws 'oh no'\n"
-              "  Actual: <Closure: () => dynamic>\n"
+              "  Actual: <$closureString>\n"
               "   Which: threw 'aw dang'\n");
         });
       });
@@ -132,7 +132,7 @@ void main() {
         }).then((liveTest) {
           expectTestFailed(liveTest, startsWith(
               "Expected: throws 'oh no'\n"
-              "  Actual: <Closure: () => dynamic>\n"
+              "  Actual: <$closureString>\n"
               "   Which: threw 'aw dang'\n"));
         });
       });

test/utils.dart

@@ -15,6 +15,11 @@ import 'package:unittest/src/runner/load_exception.dart';
 import 'package:unittest/src/util/remote_exception.dart';
 import 'package:unittest/unittest.dart';
 
+/// The string representation of an untyped closure with no arguments.
+///
+/// This differs between dart2js and the VM.
+final String closureString = (() {}).toString();
+
 // The last state change detected via [expectStates].
 State lastState;