Sanitize data before providing it to the CDM

media/cdm/key_system_names.cc

Index: media/cdm/key_system_names.cc
diff --git a/media/cdm/key_system_names.cc b/media/cdm/key_system_names.cc
index f0abaf0574724115cd34d2d8002fb462b093093e..eed84539a6cdf84a18386e1cbd14d8d87039f5d6 100644
--- a/media/cdm/key_system_names.cc
+++ b/media/cdm/key_system_names.cc
@@ -11,6 +11,10 @@ namespace media {
 const char kClearKey[] = "org.w3.clearkey";
 const char kExternalClearKey[] = "org.chromium.externalclearkey";
 
+bool IsClearKey(const std::string& key_system) {
+  return key_system == kClearKey;
+}
+
 bool IsParentKeySystemOf(const std::string& parent_key_system,
                          const std::string& key_system) {
   std::string prefix = parent_key_system + '.';