Disabling two WebRTC browser tests to allow WebRTC roll in.

This allows to reland the following WebRTC change that was reverted:
https://webrtc-review.googlesource.com/c/src/+/65700
The tests will be updated once the change is rolled in.

Bug: webrtc:7933
Change-Id: I7e8b3a0b4772d73a7e74a077310a9fa9cda331c2
Reviewed-on: https://chromium-review.googlesource.com/989025
Commit-Queue: Seth Hampson <shampson@chromium.org>
Reviewed-by: Sergey Ulanov <sergeyu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#547516}

chrome/browser/media/webrtc/webrtc_rtp_browsertest.cc

@@ -397,12 +397,33 @@ IN_PROC_BROWSER_TEST_F(WebRtcRtpBrowserTest,
                       left_tab_));
 }
 
-IN_PROC_BROWSER_TEST_F(WebRtcRtpBrowserTest, TrackSwitchingStream) {
+// This test is disabled to allow WebRTC change to roll in that adds support
+// for multiple/no streams for a given track in Unified Plan mode. Currently the
+// correct behavior is not tested when the stream switches, and since the WebRTC
+// change adds some (more) correct behavior for this in Plan B mode it breaks.
+// This test will be updated after the roll in to test that the original track
+// gets muted and the original stream is empty after the stream switches.
+// bug: https://bugs.chromium.org/p/webrtc/issues/detail?id=7933
+IN_PROC_BROWSER_TEST_F(WebRtcRtpBrowserTest, DISABLED_TrackSwitchingStream) {
   StartServerAndOpenTabs();
   EXPECT_EQ("ok", ExecuteJavascript("trackSwitchingStream()", left_tab_));
 }
 
-IN_PROC_BROWSER_TEST_F(WebRtcRtpBrowserTest, TrackAddedToSecondStream) {
+// This test is disabled to allow WebRTC change to roll in that adds support
+// for multiple/no streams for a given track in Unified Plan mode. This
+// test breaks with the update because the SDP is parsed differently to support
+// multiple a=msid lines and for Plan B mode only the first media stream ID is
+// used. Currently this doesn't test the desired behavior, because the SDP
+// parsing uses the last a=msid line, which ends up just testing the stream
+// switching (as tested above already). Once the update is rolled in we can
+// either:
+// A: Remove this test because it only can be done with SDP munging, and it is
+//    not supported with Plan B SDP semantics.
+// B: Test this case for Unified Plan, assuming SDP munging. In this case
+//    according to the w3 WebRTC spec we will not add the new stream.
+// bug: https://bugs.chromium.org/p/webrtc/issues/detail?id=7933
+IN_PROC_BROWSER_TEST_F(WebRtcRtpBrowserTest,
+                       DISABLED_TrackAddedToSecondStream) {
   StartServerAndOpenTabs();
   EXPECT_EQ("ok", ExecuteJavascript("trackAddedToSecondStream()", left_tab_));
 }