--- a/ipc/glue/ProtocolUtils.cpp
+++ b/ipc/glue/ProtocolUtils.cpp
@@ -751,17 +751,17 @@ IToplevelProtocol::DestroySharedMemory(S
 {
   Shmem::id_t aId = shmem.Id(Shmem::IHadBetterBeIPDLCodeCallingThis_OtherwiseIAmADoodyhead());
   Shmem::SharedMemory* segment = LookupSharedMemory(aId);
   if (!segment) {
     return false;
   }
 
   Message* descriptor = shmem.UnshareFrom(
-    Shmem::IHadBetterBeIPDLCodeCallingThis_OtherwiseIAmADoodyhead(), OtherPid(), MSG_ROUTING_CONTROL);
+    Shmem::IHadBetterBeIPDLCodeCallingThis_OtherwiseIAmADoodyhead(), MSG_ROUTING_CONTROL);
 
   mShmemMap.Remove(aId);
   Shmem::Dealloc(Shmem::IHadBetterBeIPDLCodeCallingThis_OtherwiseIAmADoodyhead(), segment);
 
   if (!GetIPCChannel()->CanSend()) {
     delete descriptor;
     return true;
   }

--- a/ipc/glue/Shmem.cpp
+++ b/ipc/glue/Shmem.cpp
@@ -482,17 +482,16 @@ Shmem::ShareTo(IHadBetterBeIPDLCodeCalli
   }
   // close the handle to the segment after it is shared
   mSegment->CloseHandle();
   return msg;
 }
 
 IPC::Message*
 Shmem::UnshareFrom(IHadBetterBeIPDLCodeCallingThis_OtherwiseIAmADoodyhead,
-                   base::ProcessId aTargetPid,
                    int32_t routingId)
 {
   AssertInvariants();
   return new ShmemDestroyed(routingId, mId);
 }
 
 void
 IPDLParamTraits<Shmem>::Write(IPC::Message* aMsg, IProtocol* aActor,

--- a/ipc/glue/Shmem.h
+++ b/ipc/glue/Shmem.h
@@ -210,17 +210,16 @@ public:
           int32_t routingId);
 
   // Stop sharing this with |aTargetPid|.  Return an IPC message that
   // contains enough information for the other process to unmap this
   // segment.  Return a new message if successful (owned by the
   // caller), nullptr if not.
   IPC::Message*
   UnshareFrom(IHadBetterBeIPDLCodeCallingThis_OtherwiseIAmADoodyhead,
-              base::ProcessId aTargetPid,
               int32_t routingId);
 
   // Return a SharedMemory instance in this process using the
   // descriptor shared to us by the process that created the
   // underlying OS shmem resource.  The contents of the descriptor
   // depend on the type of SharedMemory that was passed to us.
   static already_AddRefed<SharedMemory>
   OpenExisting(IHadBetterBeIPDLCodeCallingThis_OtherwiseIAmADoodyhead,