Interface RTCRtpReceiver and RTCPeerConnection.getReceivers() added.

chrome/browser/media/webrtc/webrtc_browsertest_base.h

Index: chrome/browser/media/webrtc/webrtc_browsertest_base.h
diff --git a/chrome/browser/media/webrtc/webrtc_browsertest_base.h b/chrome/browser/media/webrtc/webrtc_browsertest_base.h
index 98bff2fa80d2b4cb0abf1e982f58e8a9ef696848..71e0cf6897b71e19814ff21247c2a25905ffc588 100644
--- a/chrome/browser/media/webrtc/webrtc_browsertest_base.h
+++ b/chrome/browser/media/webrtc/webrtc_browsertest_base.h
@@ -10,6 +10,7 @@
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/optional.h"
 #include "chrome/browser/media/webrtc/test_stats_dictionary.h"
 #include "chrome/test/base/in_process_browser_test.h"
 
@@ -186,6 +187,11 @@ class WebRtcTestBase : public InProcessBrowserTest {
   // Add 'usedtx=1' to the offer SDP.
   void EnableOpusDtx(content::WebContents* tab) const;
 
+  void CreateAndAddStreams(content::WebContents* tab, size_t count) const;
+  void VerifyRtpReceivers(content::WebContents* tab,
+                          base::Optional<size_t> expected_num_tracks =
+                              base::Optional<size_t>()) const;
+
  private:
   void CloseInfoBarInTab(content::WebContents* tab_contents,
                          infobars::InfoBar* infobar) const;