[headless] Specify namespace in cases where it might be ambiguous

There are sub-namespaces to ::headless named storage and
switches and those will be chosen by the compiler instead of
::storage or ::switches if the compiler knows about them.

This problem appeared in jumbo builds where the compiler knew
more about all the namespaces. Fix is to either rename/remove
the sub-namespaces or to do what this patch does, prefix
storage with :: (so ::storage and ::switches) to clarify what
namespace is intended.

Bug: 883727
Change-Id: I1f6e428926f0a959787c2205f92505280d96b831
Reviewed-on: https://chromium-review.googlesource.com/1225792
Reviewed-by: Sami Kyöstilä <skyostil@chromium.org>
Commit-Queue: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#591336}
5 files changed