Add accessor methods for RTP timestamp of EncodedImage.

Intention is to make the member private, but downstream callers
must be updated to use the accessor methods first.

Bug: webrtc:9378
Change-Id: I3495bd8d545b7234fbea10abfd14f082caa420b6
Reviewed-on: https://webrtc-review.googlesource.com/82160
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24352}
diff --git a/call/rtp_video_sender_unittest.cc b/call/rtp_video_sender_unittest.cc
index b819e69..9e3290d 100644
--- a/call/rtp_video_sender_unittest.cc
+++ b/call/rtp_video_sender_unittest.cc
@@ -140,7 +140,7 @@
 TEST(RtpVideoSenderTest, SendOnOneModule) {
   uint8_t payload = 'a';
   EncodedImage encoded_image;
-  encoded_image._timeStamp = 1;
+  encoded_image.SetTimestamp(1);
   encoded_image.capture_time_ms_ = 2;
   encoded_image._frameType = kVideoFrameKey;
   encoded_image._buffer = &payload;
@@ -170,7 +170,7 @@
 TEST(RtpVideoSenderTest, SendSimulcastSetActive) {
   uint8_t payload = 'a';
   EncodedImage encoded_image;
-  encoded_image._timeStamp = 1;
+  encoded_image.SetTimestamp(1);
   encoded_image.capture_time_ms_ = 2;
   encoded_image._frameType = kVideoFrameKey;
   encoded_image._buffer = &payload;
@@ -217,7 +217,7 @@
 TEST(RtpVideoSenderTest, SendSimulcastSetActiveModules) {
   uint8_t payload = 'a';
   EncodedImage encoded_image;
-  encoded_image._timeStamp = 1;
+  encoded_image.SetTimestamp(1);
   encoded_image.capture_time_ms_ = 2;
   encoded_image._frameType = kVideoFrameKey;
   encoded_image._buffer = &payload;