Remove "using base::File" to avoid conflict (net/)

When building using Jumbo namespace aliases with the same
name may end up in the same unit, causing a conflict at
compilation. This happens for base::File and
disk_cache::File in:
net/disk_cache/simple/simple_index_file.cc
net/disk_cache/simple/simple_synchronous_entry.cc

This commit removes "using base::File" and
instead call the namespace by its full
name.

Bug: 772146
Change-Id: I7385edf04bc23d519ee8800bc4941807a85340ad
Reviewed-on: https://chromium-review.googlesource.com/1120252
Reviewed-by: Josh Karlin <jkarlin@chromium.org>
Commit-Queue: Oscar Johansson <oscarj@opera.com>
Cr-Commit-Position: refs/heads/master@{#571880}
2 files changed