Allow suppressed EME canPlayType() responses to be overridden with a flag.

webkit/renderer/media/crypto/key_systems.cc

Index: webkit/renderer/media/crypto/key_systems.cc
diff --git a/webkit/renderer/media/crypto/key_systems.cc b/webkit/renderer/media/crypto/key_systems.cc
index 6ece643481589e5647b95353734333a3cfce97ae..2d056b3b31f6f958fdd53156ab130d6dfaa64df4 100644
--- a/webkit/renderer/media/crypto/key_systems.cc
+++ b/webkit/renderer/media/crypto/key_systems.cc
@@ -112,6 +112,11 @@ bool KeySystems::IsSupportedKeySystemWithMediaMimeType(
     const std::string& mime_type,
     const std::vector<std::string>& codecs,
     const std::string& key_system) {
+  // This method is only used by the canPlaytType() path (not the EME methods),
+  // so we check for suppressed key_systems here.
+  if(IsCanPlayTypeSuppressed(key_system))
+    return false;
+
   if (codecs.empty())
     return IsSupportedKeySystemWithContainerAndCodec(
         mime_type, std::string(), key_system);