Revert of FrameBuffer for the new jitter buffer. (patchset #9 id:160001 of https://codereview.webrtc.org/1969403007/ )

Reason for revert:
Two tests added by this CL failed in Win DrMemory Full:
 TestFrameBuffer2.OneLayerStreamReordered - TestFrameBuffer2.WaitForFrame

See the link here:
https://build.chromium.org/p/client.webrtc/waterfall?builder=Win%20DrMemory%20Full

Original issue's description:
> FrameBuffer for the new jitter buffer.
>
> BUG=webrtc:5514
> R=danilchap@webrtc.org, mflodman@webrtc.org
>
> Committed: https://crrev.com/a376e70cf9d0df3c35d53533b454da542661775b
> Cr-Commit-Position: refs/heads/master@{#12798}

TBR=mflodman@webrtc.org,danilchap@webrtc.org,philipel@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:5514

Review-Url: https://codereview.webrtc.org/1991513004
Cr-Commit-Position: refs/heads/master@{#12800}

webrtc/modules/video_coding/timing.h

@@ -28,7 +28,7 @@ class VCMTiming {
   // The primary timing component should be passed
   // if this is the dual timing component.
   explicit VCMTiming(Clock* clock, VCMTiming* master_timing = NULL);
-  virtual ~VCMTiming();
+  ~VCMTiming();
 
   // Resets the timing to the initial state.
   void Reset();
@@ -69,11 +69,11 @@ class VCMTiming {
   // Returns the receiver system time when the frame with timestamp
   // frame_timestamp should be rendered, assuming that the system time currently
   // is now_ms.
-  virtual int64_t RenderTimeMs(uint32_t frame_timestamp, int64_t now_ms) const;
+  int64_t RenderTimeMs(uint32_t frame_timestamp, int64_t now_ms) const;
 
   // Returns the maximum time in ms that we can wait for a frame to become
   // complete before we must pass it to the decoder.
-  virtual uint32_t MaxWaitingTime(int64_t render_time_ms, int64_t now_ms) const;
+  uint32_t MaxWaitingTime(int64_t render_time_ms, int64_t now_ms) const;
 
   // Returns the current target delay which is required delay + decode time +
   // render delay.