The modified assertions targeted the property descriptor for the
template object's first "cooked" value. The code immediately preceeding
these statements asserts these values.

Update the assertions to instead target the property descriptor for the
template object's first "raw" value (which are otherwise untested).

BUG=

Review URL: https://codereview.chromium.org/1049523003

Cr-Commit-Position: refs/heads/master@{#27566}