Improve VM connection flow in Observatory

Improve VM connection flow in Observatory

- [x] Don't show "(Connected)" next to a VM we aren't connected to.
- [x] Navigate to the vm-connect page if we get an initial connection error.
- [x] Fix regression of the 'vm disconnected' notification bubble not appearing.
- [x] Use the Uris helper class instead of hard coded paths
- [x] Improve user inputted URI normalization
- [x] Ignore network errors on stream subscription requests
- [x] On first launch, attempt to connect to the default target and not the last target connected to.

BUG=
R=rmacnak@google.com

Committed: https://github.com/dart-lang/sdk/commit/72b79d970baa8a2cea93e0cb3b0e2d50fc17d473

[Cutch, 2016-09-15 01:11:55]

Description was changed from

==========
Improve VM connection flow

BUG=
==========

to

==========
Improve VM connection flow

- [x] Don't show "(Connected)" next to a VM we aren't connected to.
- [x] Navigate to the vm-connect page if we get an initial connection error.
- [x] Fix regression of the 'vm disconnected' notification bubble not appearing.
- [x] Use the Uris helper class instead of hard coded paths
- [x] Improve user inputted URI normalization 
- [x] Ignore network errors on stream subscription requests

BUG=
==========

[Cutch, 2016-09-15 15:51:35]

Description was changed from

==========
Improve VM connection flow

- [x] Don't show "(Connected)" next to a VM we aren't connected to.
- [x] Navigate to the vm-connect page if we get an initial connection error.
- [x] Fix regression of the 'vm disconnected' notification bubble not appearing.
- [x] Use the Uris helper class instead of hard coded paths
- [x] Improve user inputted URI normalization 
- [x] Ignore network errors on stream subscription requests

BUG=
==========

to

==========
Improve VM connection flow in Observatory

- [x] Don't show "(Connected)" next to a VM we aren't connected to.
- [x] Navigate to the vm-connect page if we get an initial connection error.
- [x] Fix regression of the 'vm disconnected' notification bubble not appearing.
- [x] Use the Uris helper class instead of hard coded paths
- [x] Improve user inputted URI normalization 
- [x] Ignore network errors on stream subscription requests

BUG=
==========

[Cutch, 2016-09-15 17:24:34]

johnmccutchan@google.com changed reviewers:
+ rmacnak@google.com

[Cutch, 2016-09-15 17:24:35]

PTAL

[rmacnak, 2016-09-15 17:55:57]

lgtm


Just noting some remaining issues:
 - I've seen some invalid vm addresses listed, like
'ws://http://127.0.0.1:49770//ws'
 - We seem to prefer connecting to the previously connected port over the same
port as the UI. So when using --observe=8282 then using --observe=8383, the
second time I'm landed at the connection page instead of connecting to the VM at
8383.

[Cutch, 2016-09-15 18:15:52]

Description was changed from

==========
Improve VM connection flow in Observatory

- [x] Don't show "(Connected)" next to a VM we aren't connected to.
- [x] Navigate to the vm-connect page if we get an initial connection error.
- [x] Fix regression of the 'vm disconnected' notification bubble not appearing.
- [x] Use the Uris helper class instead of hard coded paths
- [x] Improve user inputted URI normalization 
- [x] Ignore network errors on stream subscription requests

BUG=
==========

to

==========
Improve VM connection flow in Observatory

- [x] Don't show "(Connected)" next to a VM we aren't connected to.
- [x] Navigate to the vm-connect page if we get an initial connection error.
- [x] Fix regression of the 'vm disconnected' notification bubble not appearing.
- [x] Use the Uris helper class instead of hard coded paths
- [x] Improve user inputted URI normalization 
- [x] Ignore network errors on stream subscription requests
- [x] On first launch, attempt to connect to the default target and not the last
target connected to.

BUG=
==========

[Cutch, 2016-09-15 18:17:36]

The weird addresses are stale state that you'll have to remove manually.

I've fixed the default target problem.

[Cutch, 2016-09-15 18:29:12]

Description was changed from

==========
Improve VM connection flow in Observatory

- [x] Don't show "(Connected)" next to a VM we aren't connected to.
- [x] Navigate to the vm-connect page if we get an initial connection error.
- [x] Fix regression of the 'vm disconnected' notification bubble not appearing.
- [x] Use the Uris helper class instead of hard coded paths
- [x] Improve user inputted URI normalization 
- [x] Ignore network errors on stream subscription requests
- [x] On first launch, attempt to connect to the default target and not the last
target connected to.

BUG=
==========

to

==========
Improve VM connection flow in Observatory

- [x] Don't show "(Connected)" next to a VM we aren't connected to.
- [x] Navigate to the vm-connect page if we get an initial connection error.
- [x] Fix regression of the 'vm disconnected' notification bubble not appearing.
- [x] Use the Uris helper class instead of hard coded paths
- [x] Improve user inputted URI normalization
- [x] Ignore network errors on stream subscription requests
- [x] On first launch, attempt to connect to the default target and not the last
target connected to.

BUG=
R=rmacnak@google.com

Committed:
https://github.com/dart-lang/sdk/commit/72b79d970baa8a2cea93e0cb3b0e2d50fc17d473
==========

[Cutch, 2016-09-15 18:29:14]

Committed patchset #4 (id:60001) manually as
72b79d970baa8a2cea93e0cb3b0e2d50fc17d473 (presubmit successful).