* runs ios unit tests, if the simulator is already booted.
* address reviewer comments
* changing comments for the Safari desktop tests
* addressing reviewer comments. removing the timeout.
* change mobile browsers ver name for safari.dart
* removing then calback on browser exit, only leaving the exception callback
* Add Edge support for Flutter Engine unit-tests. This does not include the launcher
* Add mapping from browser name to platform.
* remove ie from supported browser maps
* Launch safari browser
* Adding safari tests to supported browsers
* changing the directrory for redirect file. This works without opening a permision pop-up. Note: there is no headless mode in safari
* addressing reviewer comments
* changes to add firefox as one of the browser options to test_platform and test_runner
* Creating a supported_browsers file to put all the different browser related maps and utilities
* Remove accidentaly forgotten commented out lines. Clear imports
* fix error in screenshot handler
* Addressing PR comments.
* addressing PR comments part 2: