Bug 1438272 - Part 3: move session history to parent process. r=nika

Differential Revision: https://phabricator.services.mozilla.com/D26904

docshell/build/nsDocShellModule.cpp

@@ -6,6 +6,7 @@
 
 #include "mozilla/dom/BrowsingContext.h"
 #include "mozilla/dom/BrowsingContextGroup.h"
+#include "mozilla/dom/SHEntryChild.h"
 
 // session history
 #include "nsSHEntryShared.h"
@@ -18,6 +19,7 @@ nsresult InitDocShellModule() {
   mozilla::dom::BrowsingContext::Init();
   nsresult rv = nsSHistory::Startup();
   NS_ENSURE_SUCCESS(rv, rv);
+  mozilla::dom::SHEntryChildShared::Init();
 
   return NS_OK;
 }