Remove deprecated i420 buffer pool

Bug: webrtc:11956
Change-Id: I343cc995bb8785ccc9e90e4660028207a6f0f0a1
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/185121
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32174}
diff --git a/common_video/BUILD.gn b/common_video/BUILD.gn
index 5452520..9cb6f45 100644
--- a/common_video/BUILD.gn
+++ b/common_video/BUILD.gn
@@ -27,7 +27,6 @@
     "h264/sps_vui_rewriter.cc",
     "h264/sps_vui_rewriter.h",
     "include/bitrate_adjuster.h",
-    "include/i420_buffer_pool.h",
     "include/incoming_video_stream.h",
     "include/quality_limitation_reason.h",
     "include/video_frame_buffer.h",
diff --git a/common_video/include/i420_buffer_pool.h b/common_video/include/i420_buffer_pool.h
deleted file mode 100644
index 689fb3e..0000000
--- a/common_video/include/i420_buffer_pool.h
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-
-#ifndef COMMON_VIDEO_INCLUDE_I420_BUFFER_POOL_H_
-#define COMMON_VIDEO_INCLUDE_I420_BUFFER_POOL_H_
-
-#include <stddef.h>
-
-#include <list>
-
-#include "api/scoped_refptr.h"
-#include "api/video/i420_buffer.h"
-#include "common_video/include/video_frame_buffer_pool.h"
-#include "rtc_base/race_checker.h"
-#include "rtc_base/ref_counted_object.h"
-
-namespace webrtc {
-
-// Deprecated. Use VideoFrameBufferPool instead.
-class I420BufferPool : public VideoFrameBufferPool {
- public:
-  I420BufferPool() : VideoFrameBufferPool() {}
-  explicit I420BufferPool(bool zero_initialize)
-      : VideoFrameBufferPool(zero_initialize) {}
-  I420BufferPool(bool zero_initialze, size_t max_number_of_buffers)
-      : VideoFrameBufferPool(zero_initialze, max_number_of_buffers) {}
-  ~I420BufferPool() = default;
-
-  rtc::scoped_refptr<I420Buffer> CreateBuffer(int width, int height) {
-    return VideoFrameBufferPool::CreateI420Buffer(width, height);
-  }
-};
-
-}  // namespace webrtc
-
-#endif  // COMMON_VIDEO_INCLUDE_I420_BUFFER_POOL_H_