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

tests/html/isolates_test.dart

 #library('IsolatesTest');
 #import('../../pkg/unittest/unittest.dart');
 #import('../../pkg/unittest/html_config.dart');
 #import('dart:html');
 #import('dart:json');
 #import('dart:isolate', prefix:'isolate');
 
 String responseFor(message) => 'response for $message';
 
 void isolateEntry() {
   bool wasThrown = false;
   try {
     window.alert('Test');
-  } catch(final e) {
+  } catch (e) {
     wasThrown = true;
   }
   // If wasn't thrown, do not listen to messages to make test fail.
   if (!wasThrown) {
     return;
   }
 
   // Check that JSON library was loaded to isolate.
   JSON.stringify([1, 2, 3]);
 
@@ skipping 18 matching lines @@
         port.call(msg2).then((response) {
           guardAsync(() {
             Expect.equals(responseFor(msg2), response);
             callback();
           });
         });
       });
     });
   });
 }