(3) Rename files to snake_case: move the files

Mechanically generated with this command:

tools_webrtc/do-rename.sh move all-renames.txt

Bug: webrtc:10159
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Change-Id: I8b05b6eab9b9d18b29c2199bbea239e9add1e690
Reviewed-on: https://webrtc-review.googlesource.com/c/115481
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26225}

api/rtp_receiver_interface.cc

@@ -0,0 +1,56 @@
+/*
+ *  Copyright 2018 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.
+ */
+
+#include "api/rtpreceiverinterface.h"
+
+namespace webrtc {
+
+RtpSource::RtpSource(int64_t timestamp_ms,
+                     uint32_t source_id,
+                     RtpSourceType source_type)
+    : timestamp_ms_(timestamp_ms),
+      source_id_(source_id),
+      source_type_(source_type) {}
+
+RtpSource::RtpSource(int64_t timestamp_ms,
+                     uint32_t source_id,
+                     RtpSourceType source_type,
+                     uint8_t audio_level)
+    : timestamp_ms_(timestamp_ms),
+      source_id_(source_id),
+      source_type_(source_type),
+      audio_level_(audio_level) {}
+
+RtpSource::RtpSource(const RtpSource&) = default;
+RtpSource& RtpSource::operator=(const RtpSource&) = default;
+RtpSource::~RtpSource() = default;
+
+std::vector<std::string> RtpReceiverInterface::stream_ids() const {
+  return {};
+}
+
+std::vector<rtc::scoped_refptr<MediaStreamInterface>>
+RtpReceiverInterface::streams() const {
+  return {};
+}
+
+std::vector<RtpSource> RtpReceiverInterface::GetSources() const {
+  return {};
+}
+
+void RtpReceiverInterface::SetFrameDecryptor(
+    rtc::scoped_refptr<FrameDecryptorInterface> frame_decryptor) {}
+
+rtc::scoped_refptr<FrameDecryptorInterface>
+RtpReceiverInterface::GetFrameDecryptor() const {
+  return nullptr;
+}
+
+}  // namespace webrtc