tools/vim: Update ycmd configuration.

1) Update the default flags added to all command lines to reflect the fact that
   Chromium is currently compiled with --std=c++14.
2) The default file in the Blink tree (Source/core/Init.cpp) doesn't
   exist anymore. Source/core/CoreInitializer.cpp will be used instead.

Bug: 
Change-Id: I07d5f8a9a3a5001b6a4cdcd65625000fb21ed282
Tested: Atom with YouCompleteMe on Mac works correctly after changes.
Reviewed-on: https://chromium-review.googlesource.com/618172
Reviewed-by: Scott Graham <scottmg@chromium.org>
Commit-Queue: Victor Costan <pwnall@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#495303}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 3c2db7d3f0fd55edace7857fc3c263e26eb05ba2
2 files changed