Split out spdy_log_util from http_log_util.

Motivation: ElideHeaderValueForNetLog() is used in HttpRequestHeaders
and HttpResponseHeaders, therefore must be included in a nacl build.  On
the other hand, ElideGoAwayDebugDataForNetLog() and
ElideSpdyHeaderBlockForNetLog(), and their dependencies including
SpdyHeaderBlock, UnsafeArena, and linked_hash_map, do not need to be
included in a nacl build.  This CL splits out these functions from
http_log_util into spdy_log_util, and reverts the build changes that I
made in https://crrev.com/2622703002.

Also remove NetLogCaptureMode forward declaration: instances are passed by
value, therefore declaration has to be included.

Also use |auto headers_list = base::MakeUnique| instead of |unique_ptr
headers_list(new)| in ElideSpdyHeaderBlockForNetLog().

Also add unittest for ElideSpdyHeaderBlockForNetLog().

Review-Url: https://codereview.chromium.org/2771033005
Cr-Original-Commit-Position: refs/heads/master@{#459454}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 4fab802da9defe20515b8da9ab72e9017bded970
10 files changed