Bug 1489317: Part 4 - Add asssertion that COM is initialized on the thread that is resolving an agile reference; r=mhowell

Depends on D5321

Differential Revision: https://phabricator.services.mozilla.com/D5323

--HG--
extra : moz-landing-system : lando

ipc/mscom/AgileReference.cpp

@@ -6,10 +6,11 @@
 
 #include "mozilla/mscom/AgileReference.h"
 
+#include "mozilla/Assertions.h"
 #include "mozilla/DebugOnly.h"
 #include "mozilla/DynamicallyLinkedFunctionPtr.h"
-#include "mozilla/Assertions.h"
 #include "mozilla/Move.h"
+#include "mozilla/mscom/Utils.h"
 
 #if NTDDI_VERSION < NTDDI_WINBLUE
 
@@ -137,6 +138,7 @@ AgileReference::Resolve(REFIID aIid, void** aOutInterface) const
 {
   MOZ_ASSERT(aOutInterface);
   MOZ_ASSERT(mAgileRef || mGitCookie);
+  MOZ_ASSERT(IsCOMInitializedOnCurrentThread());
 
   if (!aOutInterface) {
     return E_INVALIDARG;

ipc/mscom/Utils.cpp

@@ -32,6 +32,15 @@ extern "C" IMAGE_DOS_HEADER __ImageBase;
 namespace mozilla {
 namespace mscom {
 
+bool
+IsCOMInitializedOnCurrentThread()
+{
+  APTTYPE aptType;
+  APTTYPEQUALIFIER aptTypeQualifier;
+  HRESULT hr = CoGetApartmentType(&aptType, &aptTypeQualifier);
+  return hr != CO_E_NOTINITIALIZED;
+}
+
 bool
 IsCurrentThreadMTA()
 {

ipc/mscom/Utils.h

@@ -20,6 +20,7 @@ struct IUnknown;
 namespace mozilla {
 namespace mscom {
 
+bool IsCOMInitializedOnCurrentThread();
 bool IsCurrentThreadMTA();
 bool IsProxy(IUnknown* aUnknown);
 bool IsValidGUID(REFGUID aCheckGuid);

widget/windows/JumpListBuilder.cpp

@@ -229,6 +229,8 @@ NS_IMETHODIMP JumpListBuilder::InitListBuild(JSContext* aCx,
 
 void JumpListBuilder::DoInitListBuild(RefPtr<Promise>&& aPromise)
 {
+  // Since we're invoking COM interfaces to talk to the shell on a background
+  // thread, we need to be running inside a single-threaded apartment.
   mscom::STARegion sta;
   MOZ_ASSERT(sta.IsValid());
 
@@ -515,6 +517,8 @@ NS_IMETHODIMP JumpListBuilder::CommitListBuild(nsIJumpListCommittedCallback* aCa
 
 void JumpListBuilder::DoCommitListBuild(RefPtr<detail::DoneCommitListBuildCallback> aCallback)
 {
+  // Since we're invoking COM interfaces to talk to the shell on a background
+  // thread, we need to be running inside a single-threaded apartment.
   mscom::STARegion sta;
   MOZ_ASSERT(sta.IsValid());