--- a/docshell/base/BrowsingContext.cpp
+++ b/docshell/base/BrowsingContext.cpp
@@ -510,9 +510,51 @@ already_AddRefed<BrowsingContext> Browsi
   RefPtr<BrowsingContext> bc;
   if (childDS) {
     childDS->GetBrowsingContext(getter_AddRefs(bc));
   }
   return bc.forget();
 }
 
 }  // namespace dom
+
+namespace ipc {
+
+void IPDLParamTraits<dom::BrowsingContext>::Write(
+    IPC::Message* aMsg, IProtocol* aActor, dom::BrowsingContext* aParam) {
+  uint64_t id = aParam ? aParam->Id() : 0;
+  WriteIPDLParam(aMsg, aActor, id);
+
+  // If his is an in-process send. We want to make sure that our BrowsingContext
+  // object lives long enough to make it to the other side, so we take an extra
+  // reference. This reference is freed in ::Read().
+  if (!aActor->GetIPCChannel()->IsCrossProcess()) {
+    NS_IF_ADDREF(aParam);
+  }
+}
+
+bool IPDLParamTraits<dom::BrowsingContext>::Read(
+    const IPC::Message* aMsg, PickleIterator* aIter, IProtocol* aActor,
+    RefPtr<dom::BrowsingContext>* aResult) {
+  uint64_t id = 0;
+  if (!ReadIPDLParam(aMsg, aIter, aActor, &id)) {
+    return false;
+  }
+
+  if (id == 0) {
+    aResult = nullptr;
+    return true;
+  }
+
+  *aResult = dom::BrowsingContext::Get(id);
+  MOZ_ASSERT(aResult, "Deserialized absent BrowsingContext!");
+
+  // If this is an in-process actor, free the reference taken in ::Write().
+  if (!aActor->GetIPCChannel()->IsCrossProcess()) {
+    dom::BrowsingContext* bc = *aResult;
+    NS_IF_RELEASE(bc);
+  }
+
+  return aResult != nullptr;
+}
+
+}  // namespace ipc
 }  // namespace mozilla

--- a/docshell/base/BrowsingContext.h
+++ b/docshell/base/BrowsingContext.h
@@ -15,23 +15,35 @@
 #include "nsCycleCollectionParticipant.h"
 #include "nsIDocShell.h"
 #include "nsString.h"
 #include "nsTArray.h"
 #include "nsWrapperCache.h"
 
 class nsGlobalWindowOuter;
 class nsOuterWindowProxy;
+class PickleIterator;
+
+namespace IPC {
+class Message;
+}  // namespace IPC
 
 namespace mozilla {
 
 class ErrorResult;
 class LogModule;
 class OOMReporter;
 
+namespace ipc {
+class IProtocol;
+
+template <typename T>
+struct IPDLParamTraits;
+}  // namespace ipc
+
 namespace dom {
 
 class BrowsingContextGroup;
 class ContentParent;
 template <typename>
 struct Nullable;
 template <typename T>
 class Sequence;
@@ -249,11 +261,22 @@ class BrowsingContext : public nsWrapper
  * lives in this process, and a same-process WindowProxy should be used (see
  * nsGlobalWindowOuter). This should only be called by bindings code, ToJSValue
  * is the right API to get a WindowProxy for a BrowsingContext.
  */
 extern bool GetRemoteOuterWindowProxy(JSContext* aCx, BrowsingContext* aContext,
                                       JS::MutableHandle<JSObject*> aRetVal);
 
 }  // namespace dom
+
+// Allow sending BrowsingContext objects over IPC.
+namespace ipc {
+template <>
+struct IPDLParamTraits<dom::BrowsingContext> {
+  static void Write(IPC::Message* aMsg, IProtocol* aActor,
+                    dom::BrowsingContext* aParam);
+  static bool Read(const IPC::Message* aMsg, PickleIterator* aIter,
+                   IProtocol* aActor, RefPtr<dom::BrowsingContext>* aResult);
+};
+}  // namespace ipc
 }  // namespace mozilla
 
 #endif  // !defined(mozilla_dom_BrowsingContext_h)

--- a/dom/ipc/WindowGlobalParent.h
+++ b/dom/ipc/WindowGlobalParent.h
@@ -17,16 +17,17 @@ class nsIURI;
 class nsFrameLoader;
 
 namespace mozilla {
 namespace dom {
 
 class CanonicalBrowsingContext;
 class WindowGlobalChild;
 class JSWindowActorParent;
+class TabParent;
 
 /**
  * A handle in the parent process to a specific nsGlobalWindowInner object.
  */
 class WindowGlobalParent final : public nsISupports,
                                  public nsWrapperCache,
                                  public PWindowGlobalParent {
   friend class PWindowGlobalParent;