Refactor voe::Channel to not use RtpReceiver.

Analogous to https://webrtc-review.googlesource.com/c/src/+/92398, for
RtpVideoStreamReceiver.

Bug: webrtc:7135
Change-Id: I0639f9982da2ed80edbcf900cf14f8ae982ef80c
Reviewed-on: https://webrtc-review.googlesource.com/93820
Commit-Queue: Niels Moller <nisse@webrtc.org>
Reviewed-by: Oskar Sundbom <ossu@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24309}
diff --git a/modules/rtp_rtcp/source/contributing_sources.cc b/modules/rtp_rtcp/source/contributing_sources.cc
index 9b82de5..853706c 100644
--- a/modules/rtp_rtcp/source/contributing_sources.cc
+++ b/modules/rtp_rtcp/source/contributing_sources.cc
@@ -14,15 +14,13 @@
 
 namespace {
 
-// Set by the spec, see
-// https://www.w3.org/TR/webrtc/#dom-rtcrtpreceiver-getcontributingsources
-constexpr int64_t kHistoryMs = 10 * rtc::kNumMillisecsPerSec;
-
 // Allow some stale records to accumulate before cleaning.
 constexpr int64_t kPruningIntervalMs = 15 * rtc::kNumMillisecsPerSec;
 
 }  // namespace
 
+constexpr int64_t ContributingSources::kHistoryMs;
+
 ContributingSources::ContributingSources() = default;
 ContributingSources::~ContributingSources() = default;