Expand PrefHashBrowserTest to ensure unloaded profile initialization produces proper hashes.
Expand PrefHashBrowserTest to ensure unloaded profile initialization produces proper hashes.

This is done by ensuring that only Unchanged stats are generated when explicitly loading the second profile.

This is a regression test for a regression that was about to be introduced in patch set 43 of https://codereview.chromium.org/114223002/#ps3400001 (basically the merge made it such that PrefHashFilter::Initialize -- which was just introduced after writting that CL -- would now use pref_hash_store_ directly to StoreHash where as this is wrong for split prefs; I will make this impossible in a following patch set of the afore-mentioned CL).

The technique used to inspect histograms is akin to the one that was removed from the initial pref_metrics_service_unittest.cc in https://codereview.chromium.org/90563003.

BUG=329078,336478
TEST=New test passes on trunk, but fails on top of patch set 43 of afore-mentioned CL.

Review URL: https://codereview.chromium.org/137383011

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@248032 0039d316-1c4b-4281-b951-d872f2087c98

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