Combine 'pssh' parsing routines.

media/formats/mp4/box_definitions.h

Index: media/formats/mp4/box_definitions.h
diff --git a/media/formats/mp4/box_definitions.h b/media/formats/mp4/box_definitions.h
index 026effe6b5fbd3fe036e63426400c03f288802a5..2dfab63b5d17c06ad1fc0dd56151ebd5057a2249 100644
--- a/media/formats/mp4/box_definitions.h
+++ b/media/formats/mp4/box_definitions.h
@@ -44,13 +44,23 @@ struct MEDIA_EXPORT FileType : Box {
   uint32 minor_version;
 };
 
+// If only copying the 'pssh' boxes, use ProtectionSystemSpecificHeader.
+// If access to the individual fields is needed, use
+// FullProtectionSystemSpecificHeader.
 struct MEDIA_EXPORT ProtectionSystemSpecificHeader : Box {
   DECLARE_BOX_METHODS(ProtectionSystemSpecificHeader);
 
-  std::vector<uint8> system_id;
   std::vector<uint8> raw_box;
 };
 
+struct MEDIA_EXPORT FullProtectionSystemSpecificHeader : Box {
+  DECLARE_BOX_METHODS(FullProtectionSystemSpecificHeader);
+
+  std::vector<uint8> system_id;
+  std::vector<std::vector<uint8>> key_ids;
+  std::vector<uint8> data;
+};
+
 struct MEDIA_EXPORT SampleAuxiliaryInformationOffset : Box {
   DECLARE_BOX_METHODS(SampleAuxiliaryInformationOffset);