Delete deprecated RtpSource timestamp_ms constructor and accessor

Bug: webrtc:13756
Change-Id: Ic43cf82451785b4fbe184fce466e77b16b2c781a
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/319581
Reviewed-by: Björn Terelius <terelius@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#40765}
diff --git a/api/transport/rtp/rtp_source.h b/api/transport/rtp/rtp_source.h
index 03eeb25..11149f5 100644
--- a/api/transport/rtp/rtp_source.h
+++ b/api/transport/rtp/rtp_source.h
@@ -56,31 +56,12 @@
         extensions_(extensions),
         rtp_timestamp_(rtp_timestamp) {}
 
-  // TODO(bugs.webrtc.org/13757): Remove after 2023-09-18
-  [[deprecated]] RtpSource(int64_t timestamp_ms,
-                           uint32_t source_id,
-                           RtpSourceType source_type,
-                           uint32_t rtp_timestamp,
-                           const RtpSource::Extensions& extensions)
-      : timestamp_(Timestamp::Millis(timestamp_ms)),
-        source_id_(source_id),
-        source_type_(source_type),
-        extensions_(extensions),
-        rtp_timestamp_(rtp_timestamp) {}
-
   RtpSource(const RtpSource&) = default;
   RtpSource& operator=(const RtpSource&) = default;
   ~RtpSource() = default;
 
   Timestamp timestamp() const { return timestamp_; }
 
-  // TODO(bugs.webrtc.org/13757): Remove after 2023-09-18
-  [[deprecated]] int64_t timestamp_ms() const { return timestamp_.ms(); }
-  [[deprecated]] void update_timestamp_ms(int64_t timestamp_ms) {
-    RTC_DCHECK_LE(timestamp_.ms(), timestamp_ms);
-    timestamp_ = Timestamp::Millis(timestamp_ms);
-  }
-
   // The identifier of the source can be the CSRC or the SSRC.
   uint32_t source_id() const { return source_id_; }