Switching to RTC_ prefixed LOG macros.

Unprefixed LOG macros will be removed on 10/11/2017, this CL just
switch some LOG macros to RTC_LOG.

TBR=ilnik@webrtc.org,sprang@webrtc.org

Bug: webrtc:8452
Change-Id: I3828c145897818ded56d342eba5f7496431715a4
No-Try: True
Reviewed-on: https://webrtc-review.googlesource.com/22083
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20633}
diff --git a/modules/video_coding/generic_encoder.cc b/modules/video_coding/generic_encoder.cc
index fd642fd..271e1ae 100644
--- a/modules/video_coding/generic_encoder.cc
+++ b/modules/video_coding/generic_encoder.cc
@@ -292,8 +292,8 @@
             encode_start_list->front().encode_start_time_ms);
         encode_start_list->pop_front();
       } else {
-        LOG(LS_WARNING) << "Frame with no encode started time recordings. "
-                           "Encoder may be reordering frames.";
+        RTC_LOG(LS_WARNING) << "Frame with no encode started time recordings. "
+                               "Encoder may be reordering frames.";
       }
 
       size_t target_bitrate =