Make copying from script insets omit line numbers and breakpoint indicators.

runtime/observatory/lib/src/elements/observatory_element.dart

 // 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 observatory_element;
 
 import 'dart:async';
 import 'dart:html';
 import 'package:observatory/app.dart';
 import 'package:observatory/service.dart';
@@ skipping 178 matching lines @@
   void insertLinkIntoShadowRoot(String label, String href, [String title]) {
     var anchorElement = new AnchorElement();
     anchorElement.href = href;
     anchorElement.text = label;
     if (title != null) {
       anchorElement.title = title;
     }
     anchorElement.onClick.listen(onClickGoto);
     shadowRoot.children.add(anchorElement);
   }
+
+
+  var _onCopySubscription;
+  /// Exclude nodes from being copied, for example the line numbers and
+  /// breakpoint toggles in script insets. Must be called after [root]'s
+  /// children have been added, and only supports one node at a time.
+  void makeCssClassUncopyable(Element root, String className) {
+    var noCopyNodes = root.getElementsByClassName(className);
+    for (var node in noCopyNodes) {
+      node.style.setProperty('-moz-user-select', 'none');
+      node.style.setProperty('-khtml-user-select', 'none');
+      node.style.setProperty('-webkit-user-select', 'none');
+      node.style.setProperty('-ms-user-select', 'none');
+      node.style.setProperty('user-select', 'none');
+    }
+    if (_onCopySubscription != null) {
+      _onCopySubscription.cancel();
+    }
+    _onCopySubscription = root.onCopy.listen((event) {
+      // Mark the nodes as hidden before the copy happens, then mark them as
+      // visible on the next event loop turn.
+      for (var node in noCopyNodes) {
+        node.style.visibility = 'hidden';
+      }
+      Timer.run(() {
+        for (var node in noCopyNodes) {
+          node.style.visibility = 'visible';
+        }
+      });
+    });
+  }
 }