Disable the most flaky tests on iOS.

Disables:
 - RtpVideoSenderTest.DoesNotRetrasmitAckedPackets
 - VideoReceiveStreamTestWithFakeDecoder.RenderedFrameUpdatesGetSources

Bug: webrtc:10870, webrtc:10872, webrtc:10873
Change-Id: I410f781c30e45387c35055bf97424a68658174d3
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/148984
Commit-Queue: Sami Kalliomäki <sakal@webrtc.org>
Reviewed-by: Magnus Flodman <mflodman@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28858}
diff --git a/call/rtp_video_sender_unittest.cc b/call/rtp_video_sender_unittest.cc
index 45888a8..1fb24ab 100644
--- a/call/rtp_video_sender_unittest.cc
+++ b/call/rtp_video_sender_unittest.cc
@@ -389,7 +389,12 @@
 // Integration test verifying that ack of packet via TransportFeedback means
 // that the packet is removed from RtpPacketHistory and won't be retransmitted
 // again.
+// TODO(crbug.com/webrtc/10873): Re-enable on iOS
+#if defined(WEBRTC_IOS)
+TEST(RtpVideoSenderTest, DISABLED_DoesNotRetrasmitAckedPackets) {
+#else
 TEST(RtpVideoSenderTest, DoesNotRetrasmitAckedPackets) {
+#endif
   const int64_t kTimeoutMs = 500;
 
   RtpVideoSenderTestFixture test({kSsrc1, kSsrc2}, {kRtxSsrc1, kRtxSsrc2},
diff --git a/video/video_receive_stream_unittest.cc b/video/video_receive_stream_unittest.cc
index 6d88f67..2f9564e 100644
--- a/video/video_receive_stream_unittest.cc
+++ b/video/video_receive_stream_unittest.cc
@@ -313,7 +313,13 @@
   EXPECT_THAT(fake_renderer_.packet_infos(), ElementsAreArray(packet_infos));
 }
 
+// TODO(crbug.com/webrtc/10872): Re-enable on iOS
+#if defined(WEBRTC_IOS)
+TEST_F(VideoReceiveStreamTestWithFakeDecoder,
+       DISABLED_RenderedFrameUpdatesGetSources) {
+#else
 TEST_F(VideoReceiveStreamTestWithFakeDecoder, RenderedFrameUpdatesGetSources) {
+#endif
   constexpr uint32_t kSsrc = 1111;
   constexpr uint32_t kCsrc = 9001;
   constexpr uint32_t kRtpTimestamp = 12345;