Update almost all tests (except co19) to use the new try-catch syntax.

tests/html/window_nosuchmethod_test.dart

Index: tests/html/window_nosuchmethod_test.dart
diff --git a/tests/html/window_nosuchmethod_test.dart b/tests/html/window_nosuchmethod_test.dart
index 799b72c7d5f6935f45089dc67f67fe5535d4c6cc..d02bf1d3a9db077e278435b98b9bc631fe60b547 100644
--- a/tests/html/window_nosuchmethod_test.dart
+++ b/tests/html/window_nosuchmethod_test.dart
@@ -26,9 +26,9 @@ main() {
       try {
         String x = win.foo(message);
         Expect.fail('Should not reach here: $x');
-      } catch (NoSuchMethodException e) {
+      } on NoSuchMethodException catch (e) {
         // Expected exception.
-      } catch (Exception e) {
+      } on Exception catch (e) {
         Expect.fail('Wrong exception: $e');
       }
     });
@@ -45,10 +45,10 @@ main() {
       try {
         String x = dom.window.foo(message);
         Expect.fail('Should not reach here: $x');
-      } catch (NoSuchMethodException e) {
+      } on NoSuchMethodException catch (e) {
         // Expected exception.
-      } catch (Exception e) {
+      } on Exception catch (e) {
         Expect.fail('Wrong exception: $e');
       }
-    }); 
+    });
 }