Simplify how we load a new URL and add retries. (#1077)
Simplify how we load a new URL and add retries. (#1077)

Sometimes Chrome on a test server can take a really long time to start
to navigate, that's why we are adding a retry functionaliry so if
we try three times to wait on the actual page to finish loading.
sitespeedio/browsertime,tobli/browsertime,sitespeedio/browsertime,sitespeedio/browsertime,sitespeedio/browsertime