Fixes a double free in ContentEncoding

BUG: 127702368

Merged-In: Id7de1f8c35ef2f6458c6fb6c7751a84fe43ed1cc
Change-Id: Id17f570fe60ea2ecb3cf5cdbc179246486401005
(cherry picked from commit d2ff9ba6d9376f295b13d822d345e83841bc6189)
diff --git a/libwebm/mkvparser/mkvparser.cc b/libwebm/mkvparser/mkvparser.cc
index 87adef3..efd3545 100644
--- a/libwebm/mkvparser/mkvparser.cc
+++ b/libwebm/mkvparser/mkvparser.cc
@@ -4233,6 +4233,7 @@
         new (std::nothrow) ContentEncryption*[encryption_count];
     if (!encryption_entries_) {
       delete[] compression_entries_;
+      compression_entries_ = NULL;
       return -1;
     }
     encryption_entries_end_ = encryption_entries_;