Add browser tags to all of our tests.

test/runner/signal_test.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // Windows doesn't support sending signals.
 @TestOn("vm && !windows")
 
 import 'dart:async';
 import 'dart:io';
 
@@ skipping 32 matching lines @@
     });
 
     test("cleans up if killed while loading a browser test", () {
       d.file("test.dart", "void main() {}").create();
 
       var test = _runTest(["-p", "chrome", "test.dart"]);
       test.stdout.expect(consumeThrough(endsWith("compiling test.dart")));
       signalAndQuit(test);
 
       expectTempDirEmpty();
-    });
+    }, tags: "chrome");
 
     test("exits immediately if ^C is sent twice", () {
       d.file("test.dart", """
 void main() {
   print("in test.dart");
   while (true) {}
 }
 """).create();
 
       var test = _runTest(["test.dart"]);
@@ skipping 84 matching lines @@
     });
   });
 }
 """).create();
 
       var test = _runTest(["-p", "content-shell", "test.dart"]);
       test.stdout.expect(consumeThrough("running test"));
       signalAndQuit(test);
 
       expectTempDirEmpty();
-    });
+    }, tags: "content-shell");
 
     test("kills a VM test immediately if ^C is sent twice", () {
       d.file("test.dart", """
 import 'package:test/test.dart';
 
 void main() {
   test("test", () {
     print("running test");
     while (true) {}
   });
@@ skipping 90 matching lines @@
 
 void signalAndQuit(ScheduledProcess test) {
   test.signal(ProcessSignal.SIGTERM);
   test.shouldExit();
   test.stderr.expect(isDone);
 }
 
 void expectTempDirEmpty() {
   schedule(() => expect(new Directory(_tempDir).listSync(), isEmpty));
 }