Add observatory_pub_packages snapshot to third_party

observatory_pub_packages/unittest/coverage_controller.js

Index: observatory_pub_packages/unittest/coverage_controller.js
===================================================================
--- observatory_pub_packages/unittest/coverage_controller.js	(revision 0)
+++ observatory_pub_packages/unittest/coverage_controller.js	(working copy)
@@ -0,0 +1,31 @@
+// Copyright (c) 2011, 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.
+
+/**
+ * Coverage controller logic - used by coverage test harness to embed tests in
+ * content shell and extract coverage information.
+ */
+
+var LONG_LINE = 60000;
+
+function onReceive(e) {
+  if (e.data == 'unittest-suite-done') {
+    var s = JSON.stringify(top._$jscoverage);
+    var res = '';
+    // conent shell has a bug on lines longer than 2^16, so we split them
+    while (s.length > LONG_LINE) {
+      res += s.substr(0, LONG_LINE) + '<br>\n';
+      s = s.substr(LONG_LINE);
+    }
+    res += s;
+    window.document.body.innerHTML = res;
+    window.layoutTestController.notifyDone();
+  }
+}
+
+if (window.layoutTestController) {
+  window.layoutTestController.dumpAsText();
+  window.layoutTestController.waitUntilDone();
+  window.addEventListener("message", onReceive, false);
+}