--- a/gfx/2d/Logging.h
+++ b/gfx/2d/Logging.h
@@ -129,16 +129,17 @@ enum class LogReason : int {
   GlyphAllocFailedCairo,
   GlyphAllocFailedCG,
   InvalidRect,
   CannotDraw3D, // 20
   IncompatibleBasicTexturedEffect,
   InvalidFont,
   PAllocTextureBackendMismatch,
   GetFontFileDataFailed,
+  MessageChannelCloseFailure,
   // End
   MustBeLessThanThis = 101,
 };
 
 struct BasicLogger
 {
   // For efficiency, this method exists and copies the logic of the
   // OutputMessage below.  If making any changes here, also make it

--- a/ipc/glue/MessageChannel.cpp
+++ b/ipc/glue/MessageChannel.cpp
@@ -9,21 +9,22 @@
 #include "mozilla/ipc/ProtocolUtils.h"
 
 #include "mozilla/dom/ScriptSettings.h"
 
 #include "mozilla/Assertions.h"
 #include "mozilla/DebugOnly.h"
 #include "mozilla/Move.h"
 #include "mozilla/SizePrintfMacros.h"
+#include "mozilla/Snprintf.h"
 #include "mozilla/Telemetry.h"
+#include "mozilla/Logging.h"
 #include "nsDebug.h"
 #include "nsISupportsImpl.h"
 #include "nsContentUtils.h"
-#include "mozilla/Snprintf.h"
 
 // Undo the damage done by mozzconf.h
 #undef compress
 
 // Logging seems to be somewhat broken on b2g.
 #ifdef MOZ_B2G
 #define IPC_LOG(...)
 #else
@@ -516,16 +517,21 @@ MessageChannel::MessageChannel(MessageLi
 }
 
 MessageChannel::~MessageChannel()
 {
     MOZ_COUNT_DTOR(ipc::MessageChannel);
     IPC_ASSERT(mCxxStackFrames.empty(), "mismatched CxxStackFrame ctor/dtors");
 #ifdef OS_WIN
     BOOL ok = CloseHandle(mEvent);
+    if (!ok) {
+        gfxDevCrash(mozilla::gfx::LogReason::MessageChannelCloseFailure) <<
+            "MessageChannel failed to close. GetLastError: " <<
+            GetLastError();
+    }
     MOZ_RELEASE_ASSERT(ok);
 #endif
     Clear();
 }
 
 // This function returns the current transaction ID. Since the notion of a
 // "current transaction" can be hard to define when messages race with each
 // other and one gets canceled and the other doesn't, we require that this