Lint fix for webrtc/modules/video_coding PART 1!

Trying to submit all changes at once proved impossible since there were
too many changes in too many files. The changes to PRESUBMIT.py
will be uploaded in the last CL.
(original CL: https://codereview.webrtc.org/1528503003/)

BUG=webrtc:5309
TBR=mflodman@webrtc.org

Review URL: https://codereview.webrtc.org/1541803002

Cr-Commit-Position: refs/heads/master@{#11100}

webrtc/modules/video_coding/codecs/vp9/include/vp9.h

@@ -23,7 +23,6 @@ class VP9Encoder : public VideoEncoder {
   virtual ~VP9Encoder() {}
 };
 
-
 class VP9Decoder : public VideoDecoder {
  public:
   static VP9Decoder* Create();