[observatory] Add a 'GC' button to heap map.

tools/observatory_tool.py

 #!/usr/bin/env python
 # 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.
 """Helper for building and deploying Observatory"""
 
 import argparse
 import os
 import platform
 import shutil
@@ skipping 41 matching lines @@
 in the tools/observatory_tool.py script.
 
 """
 
 def DisplayFailureMessage():
   print """\
 
 ERROR: Observatory failed to build. What should you do?
 
 1. Revert to a working revision of the Dart VM
-2. Contact zra@, johnmccutchan@, dart-vm-team@
+2. Contact zra@, rmacnak@, dart-vm-team@
 3. File a bug: https://github.com/dart-lang/sdk/issues/new
 
 """
 
 # Run |command|. If its return code is 0, return 0 and swallow its output.
 # If its return code is non-zero, emit its output unless |always_silent| is
 # True, and return the return code.
 def RunCommand(command, always_silent=False):
   try:
     # Dart IO respects the following environment variables to configure the
@@ skipping 186 matching lines @@
     result = ExecuteCommand(options, args)
     if result == 0:
       CreateTimestampFile(options)
     return result
   except:
     DisplayFailureMessage()
 
 
 if __name__ == '__main__':
   sys.exit(main());