Spec compliant video constraints for getUserMedia behind flag.

content/public/common/content_features.cc

Index: content/public/common/content_features.cc
diff --git a/content/public/common/content_features.cc b/content/public/common/content_features.cc
index c1ccf0d87d5ceeb569a69fe126d8edfbb38cb6d1..61fc77e4961e72d26ebac184fad9573e267a09e6 100644
--- a/content/public/common/content_features.cc
+++ b/content/public/common/content_features.cc
@@ -120,6 +120,10 @@ const base::Feature kMediaDocumentDownloadButton{
     base::FEATURE_DISABLED_BY_DEFAULT
 };
 
+// Enables the old algorithm for processing video constraints in getUserMedia().
+const base::Feature kMediaStreamOldVideoConstraints{
+    "MediaStreamOldVideoConstraints", base::FEATURE_ENABLED_BY_DEFAULT};
+
 // Enables the memory coordinator.
 // WARNING:
 // The memory coordinator is not ready for use and enabling this may cause