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

tests/html/indexeddb_4_test.dart

 #library('IndexedDB4Test');
 #import('../../pkg/unittest/unittest.dart');
 #import('../../pkg/unittest/html_config.dart');
 #import('dart:html');
 
 // Test for IDBKeyRange and IDBCursor.
 
 const String DB_NAME = 'Test';
 const String STORE_NAME = 'TEST';
 const String VERSION = '1';
@@ skipping 12 matching lines @@
     db = e.target.result;
     // TODO.  Some browsers do this the w3 way - passing the VERSION to the
     // open call and listening to onversionchange.  Can we feature-detect the
     // difference and make it work?
     var request = db.setVersion(VERSION);
     request.on.success.add(
       expectAsync1((e) {
         try {
           // Nuke object store if it already exists.
           db.deleteObjectStore(STORE_NAME);
-        } catch (IDBDatabaseException e) { }
+        } on IDBDatabaseException catch (e) { }
         db.createObjectStore(STORE_NAME);
 
         var transaction = e.target.result;
         transaction.on.complete.add(expectAsync1((e) => writeItems(0)));
         transaction.on.error.add(fail);
       })
     );
     request.on.error.add(fail('setVersion error'));
   }
 
@@ skipping 95 matching lines @@
   test('upper1', test_.upper1);
   test('upper2', test_.upper2);
   test('upper3', test_.upper3);
 
   test('bound1', test_.bound1);
   test('bound2', test_.bound2);
   test('bound3', test_.bound3);
   test('bound4', test_.bound4);
   test('bound5', test_.bound5);
 }