Encrypted Media: Handle empty init_data in AesDecryptor::GenerateKeyRequest().

media/crypto/aes_decryptor.cc

Index: media/crypto/aes_decryptor.cc
diff --git a/media/crypto/aes_decryptor.cc b/media/crypto/aes_decryptor.cc
index fb16486104441837edb0b635067279ae88cd952e..88d194ea574f31bca3bf0732957f8d18fb69e247 100644
--- a/media/crypto/aes_decryptor.cc
+++ b/media/crypto/aes_decryptor.cc
@@ -139,6 +139,11 @@ bool AesDecryptor::GenerateKeyRequest(const std::string& key_system,
                                       int init_data_length) {
   std::string session_id_string(base::UintToString(next_session_id_++));
 
+  if (!init_data || !init_data_length) {
+    DVLOG(1) << "init_data required to generate a key request.";
+    return false;
+  }
+
   // For now, the AesDecryptor does not care about |key_system| and |type|;
   // just fire the event with the |init_data| as the request.
   int message_length = init_data_length;