Add webrtc/base to deprecated APIs.

PRESUBMIT.py

 # Copyright (c) 2012 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.
 
 import json
 import os
 import platform
 import re
 import subprocess
 import sys
 
 
 # Directories that will be scanned by cpplint by the presubmit script.
 CPPLINT_DIRS = [
   'webrtc/audio',
   'webrtc/call',
   'webrtc/video_engine',
 ]
 
+# List of directories of "supported" native APIs. That means changes to headers
+# will be done in a compatible way following this scheme:
+# 1. Non-breaking changes are made.
+# 2. The old APIs as marked as deprecated (with comments).
+# 3. Deprecation is announced to discuss-webrtc@googlegroups.com and
+#    webrtc-users@google.com (internal list).
+# 4. (later) The deprecated APIs are removed.
+# Directories marked as DEPRECATED should not be used. They're only present in
+# the list to support legacy downstream code.
 NATIVE_API_DIRS = (
   'talk/app/webrtc',
   'webrtc',
-  'webrtc/common_audio/include',  # DEPRECATED (will go away).
+  'webrtc/base',  # DEPRECATED.
+  'webrtc/common_audio/include',  # DEPRECATED.
   'webrtc/modules/audio_coding/include',
-  'webrtc/modules/audio_conference_mixer/include',  # DEPRECATED (will go away).
+  'webrtc/modules/audio_conference_mixer/include',  # DEPRECATED.
   'webrtc/modules/audio_device/include',
   'webrtc/modules/audio_processing/include',
   'webrtc/modules/bitrate_controller/include',
   'webrtc/modules/include',
   'webrtc/modules/remote_bitrate_estimator/include',
   'webrtc/modules/rtp_rtcp/include',
-  'webrtc/modules/rtp_rtcp/source',  # DEPRECATED (will go away).
+  'webrtc/modules/rtp_rtcp/source',  # DEPRECATED.
   'webrtc/modules/utility/include',
   'webrtc/modules/video_coding/codecs/h264/include',
   'webrtc/modules/video_coding/codecs/i420/include',
   'webrtc/modules/video_coding/codecs/vp8/include',
   'webrtc/modules/video_coding/codecs/vp9/include',
   'webrtc/modules/video_coding/include',
-  'webrtc/system_wrappers/include',  # DEPRECATED (will go away).
+  'webrtc/system_wrappers/include',  # DEPRECATED.
   'webrtc/voice_engine/include',
 )
 
 
 def _VerifyNativeApiHeadersListIsValid(input_api, output_api):
   """Ensures the list of native API header directories is up to date."""
   non_existing_paths = []
   native_api_full_paths = [
       input_api.os_path.join(input_api.PresubmitLocalPath(),
                              *path.split('/')) for path in NATIVE_API_DIRS]
@@ skipping 393 matching lines @@
     for builder in masters[master]:
       if 'presubmit' in builder:
         # Do not trigger presubmit builders, since they're likely to fail
         # (e.g. OWNERS checks before finished code review), and we're running
         # local presubmit anyway.
         pass
       else:
         try_config[master][builder] = ['defaulttests']
 
   return try_config