Merge 37191 - Merge 34903, 34928, 35008, 35549, 36054 to the 249s branch....

Merge 37191 - Merge 34903, 34928, 35008, 35549, 36054 to the 249s branch.

This pulls down two proxy changes from head:
(1) Use proxyside DNS resolution when using SOCKS v5; BUG=29914
(2) Remove implicit fallback to DIRECT when using a proxy list; BUG=12303
r34903  main SOCKS v5 DNS change
r34928  simplification of r34903
r35008  extra set of unittests for SOCKS v5
r35549  remove fallback to DIRECT for proxies
r36054  fix a regression from 35549 for singleproxy

BUG=29914, 12303, 31983
Review URL: http://codereview.chromium.org/552164

TBR=eroman@chromium.org

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=37199