IEDriver's Element.isDisplayed() should ignore opacity #503
Description
According to W3C spec draft isDisplayed method should not take opacity into account.
This is true for Firefox and Chrome drivers, checkShown_ method in atoms also explicitly ignores opacity.
But for IEDriver this is not the case. ignoreOpacity value was changed when fixing #6827, but I believe it was a mistake: this change had made IEDriver implementation inconsistent with other drivers and current spec draft.