TestPlatform.fromBrowser constructor
Creates a TestPlatform with a copy of a given BrowserPlatform.
Creates a TestBrowserPlatform from browserPlatform,
as by TestBrowserPlatform.from, and a TestPlatform
with that as its Platform.browserPlatform.
Implementation
@visibleForTesting
TestPlatform.fromBrowser(BrowserPlatform browserPlatform)
: this._browser(TestBrowserPlatform.from(browserPlatform));