Revert "Ensure correct decoding for unfiltered KSVC streams"

This reverts commit cd7c21bfadf89771690579f958bc4580588229d1.

Reason for revert: Regression in VP9 tests on perf bots

Original change's description:
> Ensure correct decoding for unfiltered KSVC streams
> 
> Set render timestamp for all frames in the superframe.
> 
> Bug: chromium:912122
> Change-Id: Ic9604620da9fb4176ad5c21b95df47fca8ddea31
> Reviewed-on: https://webrtc-review.googlesource.com/c/116985
> Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org>
> Reviewed-by: Philip Eliasson <philipel@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#26247}

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

Change-Id: I2d137d36d343bc0204ab80edb3cd55a3f89bbc33
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:912122
Reviewed-on: https://webrtc-review.googlesource.com/c/117564
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26262}
diff --git a/modules/video_coding/frame_buffer2.cc b/modules/video_coding/frame_buffer2.cc
index 2eb5866..00a8ab0 100644
--- a/modules/video_coding/frame_buffer2.cc
+++ b/modules/video_coding/frame_buffer2.cc
@@ -169,12 +169,6 @@
           frame->SetRenderTime(
               timing_->RenderTimeMs(frame->Timestamp(), now_ms));
         }
-        // If frames in superframe have different render timestamps, it will
-        // confuse jitter buffer and cause dropped frames in render queue.
-        for (size_t i = 1; i < frames_to_decode_.size(); ++i) {
-          frames_to_decode_[i]->second.frame->SetRenderTime(
-              frame->RenderTime());
-        }
         wait_ms = timing_->MaxWaitingTime(frame->RenderTime(), now_ms);
 
         // This will cause the frame buffer to prefer high framerate rather