Begin implementing a debugger page in Observatory.

runtime/bin/vmservice/observatory/lib/src/elements/stack_trace.dart

Index: runtime/bin/vmservice/observatory/lib/src/elements/stack_trace.dart
diff --git a/runtime/bin/vmservice/observatory/lib/src/elements/stack_trace.dart b/runtime/bin/vmservice/observatory/lib/src/elements/stack_trace.dart
deleted file mode 100644
index f92630eb2b8b516123da7287fcaa834a4fc28b81..0000000000000000000000000000000000000000
--- a/runtime/bin/vmservice/observatory/lib/src/elements/stack_trace.dart
+++ /dev/null
@@ -1,20 +0,0 @@
-// Copyright (c) 2013, 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.
-
-library stack_trace_element;
-
-import 'package:polymer/polymer.dart';
-import 'observatory_element.dart';
-import 'package:observatory/service.dart';
-
-@CustomTag('stack-trace')
-class StackTraceElement extends ObservatoryElement {
-  @published ServiceMap trace;
-
-  StackTraceElement.created() : super.created();
-
-  void refresh(var done) {
-    trace.reload().whenComplete(done);
-  }
-}