Add missing gmock using statements in tests.

This CL is extracted from https://crrev.com/c/1423337. The changes are
needed for a googletest roll, but are landed separately to avoid churn
in case the googletest CL is reverted.

The missing "using" statements don't currently cause build failures
because of ADL (argument-dependent lookup). However, upcoming changes in
googletest turn these omissions into compilation errors.

The crashpad diff was landed in the crashpad repository as
https://crrev.com/c/1422786.

TBR=mmenke,scottmg,thakis

Change-Id: If66000fd387ee37ae4a09b43b30659654378525a
Reviewed-on: https://chromium-review.googlesource.com/c/1423917
Reviewed-by: Victor Costan <pwnall@chromium.org>
Commit-Queue: Victor Costan <pwnall@chromium.org>
Auto-Submit: Victor Costan <pwnall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#624456}
3 files changed