Are these also 1450 errors during registry operations like this:

[ RUN      ] MediaGalleriesPlatformAppBrowserTest.GetMetadata
[844:3920:0510/204138.005:ERROR:configuration_policy_handler_list.cc(92)] Unknown policy: StringPolicy
[844:3920:0510/204138.030:ERROR:configuration_policy_handler_list.cc(92)] Unknown policy: StringPolicy
c:\b\c\b\win\src\base\test\test_reg_util_win.cc(106): error: Value of: temp_key.Create((( HKEY ) (ULONG_PTR)((LONG)0x80000001) ), key_path.c_str(), (((0x001F0000L) | (0x0001) | (0x0002) | (0x0004) | (0x0008) | (0x0010) | (0x0020)) & (~(0x00100000L))))
  Actual: 1450
Expected: 0L
Which is: 0

If so, this is the same as issue 721245. I'm not sure what's going on, but it's interesting to see that it's happening on trybots and waterfall builders (https://build.chromium.org/p/chromium.win/builders/Win%207%20Tests%20x64%20%281%29/builds/24023).

I would be suspicious of any test failure where the test is interacting with the registry. There will likely be failures that don't log the error code, so it'll be hard to know if it's truly the same issue or not.

I suspect this is the same as #2.

There's separate PrefHashBrowserTest* tests -- e.g. RegistryValidationInstance with the same issues as #2.

The other tests have errors related to registry validation as well, though not t he exact same error.

Merging to 721245, which has more context.