Remove remains of webrtc/base

PRESUBMIT.py

Index: PRESUBMIT.py
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index ca6a70a19eb3f42a516326adbf7d2a52c979cd23..d29c4c41a04a14266ccb564b86eca9884c0d80d7 100755
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -18,7 +18,6 @@ CPPLINT_BLACKLIST = [
   'tools_webrtc',
   'webrtc/api/video_codecs/video_decoder.h',
   'webrtc/api/video_codecs/video_encoder.h',
-  'webrtc/base',
   'webrtc/examples/objc',
   'webrtc/media',
   'webrtc/modules/audio_coding',
@@ -74,7 +73,6 @@ NATIVE_API_DIRS = (
 # These directories should not be used but are maintained only to avoid breaking
 # some legacy downstream code.
 LEGACY_API_DIRS = (
-  'webrtc/base',
   'webrtc/common_audio/include',
   'webrtc/modules/audio_coding/include',
   'webrtc/modules/audio_conference_mixer/include',
@@ -91,6 +89,7 @@ LEGACY_API_DIRS = (
   'webrtc/modules/video_coding/codecs/vp8/include',
   'webrtc/modules/video_coding/codecs/vp9/include',
   'webrtc/modules/video_coding/include',
+  'webrtc/rtc_base',
   'webrtc/system_wrappers/include',
   'webrtc/voice_engine/include',
 )