Ship maintain-framerate-and-resolution

Intent: https://groups.google.com/a/chromium.org/g/blink-dev/c/FUlvv_Lmk-s/m/InSaWprqAAAJ

Bug: webrtc:450044904, b/423804593
Change-Id: I56bfd745d73ce194e6ba9c43421b93cc316a2ad1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7036477
Commit-Queue: Sergey Silkin <[email protected]>
Reviewed-by: Henrik Boström <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1549089}

Author: Sergey Silkin

mst-content-hint/RTCRtpSendParameters-degradationPreference.html

@@ -31,6 +31,11 @@
   param = sender.getParameters();
   assert_equals(param.degradationPreference, 'balanced');
 
+  param.degradationPreference = 'maintain-framerate-and-resolution';
+  await sender.setParameters(param);
+  param = sender.getParameters();
+  assert_equals(param.degradationPreference, 'maintain-framerate-and-resolution');
+
   param.degradationPreference = undefined;
   await sender.setParameters(param);
   param = sender.getParameters();
@@ -91,6 +96,11 @@
   param = sender.getParameters();
   assert_equals(param.degradationPreference, 'balanced');
 
+  param.degradationPreference = 'maintain-framerate-and-resolution';
+  await sender.setParameters(param);
+  param = sender.getParameters();
+  assert_equals(param.degradationPreference, 'maintain-framerate-and-resolution');
+
   param.degradationPreference = undefined;
   await sender.setParameters(param);
   param = sender.getParameters();