* 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:
* Add Firefox installing functionality to test platform. For Linux only. Refactor test platform code
* remove download.dart. Not complete for now
* uncomment firefox.dart. Adding new CL parameters.
* Licence headers added.
* adding more comments to firefox_installer
* adding test for firefox download
* address pr comments. change directory for test in .cirrus.yml
* change directory for test_web_engine_firefox_script
* removing the system test.
* refactoring before implementing the firefox installer. This PR carries utilities to a common place. Renames the lock file with a generic name.
* Fixed README file for browser_lock
* addressing PR comments: removing unimplemented firefox methods.
