Take into account expiration time when comparing tokens.
Take into account expiration time when comparing tokens.

When refreshing a token some (misbehaving) token providers may return existing
token, but with different expiration time. It confused the token cache that
assumed expiration time is a static property of the token.

R=iannucci@chromium.org
BUG=skia:6611

Review-Url: https://codereview.chromium.org/2952323002

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