Code indentation was done with tabs in some places. Replaced with spaces.

This reverts commit e5459942.

This is the correct metric to report for compilation time benchmarks rather
than RunTime. Rename the 'gen_snapshot' value to merely 'snapshot' for
backwards compatibility and overall simplicity.

This change simplifies Dart's benchmarking of Flutter by making it easier to
adopt --report-timings (made for Dart to use), which makes the benchmarks
much more robust.

Make FlutterError objects more structured so they can be displayed better in debugging tools such as Dart DevTools.

Show appropriate error message when fonts isn't iterable

* Re-enable const

* Allow adb stdout to contain the port number without failing

* Add tests that port forwarder correctly responds to known ADB output

* Update packages
* Capture JSON RPC errors that presently get swallowed

* Added support for authentication codes for the VM service.

Previously, a valid web socket connection would use the following URI:

`ws://127.0.0.1/ws`

Now, by default, the VM service requires a connection to be made with a
URI similar to the following:

`ws://127.0.0.1:8181/Ug_U0QVsqFs=/ws`

where `Ug_U0QVsqFs` is an authentication code generated and shared by
the
service.

This behavior can be disabled with the `--disable-service-auth-codes`
flag.