Reland "Move webrtc/{base => rtc_base}" (https://codereview.webrtc.org/2877023002)

Reland the base->rtc_base without adding stub headers (will be
done in follow-up CL). This preserves git blame history of all files.

BUG=webrtc:7634
NOTRY=True
TBR=kwiberg@webrtc.org

Change-Id: Iea3bb6f3f67b8374c96337b63e8f5aa3e6181012
Reviewed-on: https://chromium-review.googlesource.com/554611
Reviewed-by: Henrik Kjellander <kjellander@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#18821}

webrtc/base/dscp.h

@@ -1,45 +0,0 @@
-/*
- *  Copyright 2013 The WebRTC Project Authors. All rights reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-
-#ifndef WEBRTC_BASE_DSCP_H_
-#define WEBRTC_BASE_DSCP_H_
-
-namespace rtc {
-// Differentiated Services Code Point.
-// See http://tools.ietf.org/html/rfc2474 for details.
-enum DiffServCodePoint {
-  DSCP_NO_CHANGE = -1,
-  DSCP_DEFAULT = 0,  // Same as DSCP_CS0
-  DSCP_CS0  = 0,   // The default
-  DSCP_CS1  = 8,   // Bulk/background traffic
-  DSCP_AF11 = 10,
-  DSCP_AF12 = 12,
-  DSCP_AF13 = 14,
-  DSCP_CS2  = 16,
-  DSCP_AF21 = 18,
-  DSCP_AF22 = 20,
-  DSCP_AF23 = 22,
-  DSCP_CS3  = 24,
-  DSCP_AF31 = 26,
-  DSCP_AF32 = 28,
-  DSCP_AF33 = 30,
-  DSCP_CS4  = 32,
-  DSCP_AF41 = 34,  // Video
-  DSCP_AF42 = 36,  // Video
-  DSCP_AF43 = 38,  // Video
-  DSCP_CS5  = 40,  // Video
-  DSCP_EF   = 46,  // Voice
-  DSCP_CS6  = 48,  // Voice
-  DSCP_CS7  = 56,  // Control messages
-};
-
-}  // namespace rtc
-
- #endif  // WEBRTC_BASE_DSCP_H_