diff --git a/dom/media/AudioSink.cpp b/dom/media/AudioSink.cpp
index 522a4c33b64c..a60ba86f91c7 100644
--- a/dom/media/AudioSink.cpp
+++ b/dom/media/AudioSink.cpp
@@ -90,7 +90,7 @@ AudioSink::Init()
   nsresult rv = NS_NewNamedThread("Media Audio",
                                   getter_AddRefs(mThread),
                                   nullptr,
-                                  MEDIA_THREAD_STACK_SIZE);
+                                  SharedThreadPool::kStackSize);
   if (NS_FAILED(rv)) {
     mEndPromise.Reject(rv, __func__);
     return p;
diff --git a/dom/media/FileBlockCache.cpp b/dom/media/FileBlockCache.cpp
index 4cc9ef219c19..b17f25aa0582 100644
--- a/dom/media/FileBlockCache.cpp
+++ b/dom/media/FileBlockCache.cpp
@@ -23,7 +23,7 @@ nsresult FileBlockCache::Open(PRFileDesc* aFD)
     MonitorAutoLock mon(mDataMonitor);
     nsresult res = NS_NewThread(getter_AddRefs(mThread),
                                 nullptr,
-                                MEDIA_THREAD_STACK_SIZE);
+                                SharedThreadPool::kStackSize);
     mIsOpen = NS_SUCCEEDED(res);
     return res;
   }
diff --git a/dom/media/SharedThreadPool.cpp b/dom/media/SharedThreadPool.cpp
index 4098d9e71114..cde6eca41b32 100644
--- a/dom/media/SharedThreadPool.cpp
+++ b/dom/media/SharedThreadPool.cpp
@@ -7,9 +7,9 @@
 #include "SharedThreadPool.h"
 #include "mozilla/ClearOnShutdown.h"
 #include "mozilla/Monitor.h"
+#include "mozilla/ReentrantMonitor.h"
 #include "mozilla/StaticPtr.h"
 #include "nsDataHashtable.h"
-#include "VideoUtils.h"
 #include "nsXPCOMCIDInternal.h"
 #include "nsComponentManagerUtils.h"
 #ifdef XP_WIN
@@ -147,7 +147,7 @@ SharedThreadPool::~SharedThreadPool()
 nsresult
 SharedThreadPool::EnsureThreadLimitIsAtLeast(uint32_t aLimit)
 {
-  // We limit the number of threads that we use for media. Note that we
+  // We limit the number of threads that we use. Note that we
   // set the thread limit to the same as the idle limit so that we're not
   // constantly creating and destroying threads (see Bug 881954). When the
   // thread pool threads shutdown they dispatch an event to the main thread
@@ -184,7 +184,7 @@ CreateThreadPool(const nsCString& aName)
   rv = pool->SetName(aName);
   NS_ENSURE_SUCCESS(rv, nullptr);
 
-  rv = pool->SetThreadStackSize(MEDIA_THREAD_STACK_SIZE);
+  rv = pool->SetThreadStackSize(SharedThreadPool::kStackSize);
   NS_ENSURE_SUCCESS(rv, nullptr);
 
 #ifdef XP_WIN
diff --git a/dom/media/SharedThreadPool.h b/dom/media/SharedThreadPool.h
index f93f1c5006a2..331773c4f1f2 100644
--- a/dom/media/SharedThreadPool.h
+++ b/dom/media/SharedThreadPool.h
@@ -10,6 +10,7 @@
 #include <queue>
 #include "mozilla/RefPtr.h"
 #include "nsThreadUtils.h"
+#include "nsIThreadManager.h"
 #include "nsIThreadPool.h"
 #include "nsISupports.h"
 #include "nsISupportsImpl.h"
@@ -66,6 +67,17 @@ public:
   // *Must* be called on the main thread.
   static void SpinUntilEmpty();
 
+#if defined(MOZ_ASAN)
+  // Use the system default in ASAN builds, because the default is assumed to be
+  // larger than the size we want to use and is hopefully sufficient for ASAN.
+  static const uint32_t kStackSize = nsIThreadManager::DEFAULT_STACK_SIZE;
+#elif defined(XP_WIN) || defined(XP_MACOSX) || defined(LINUX)
+  static const uint32_t kStackSize = (256 * 1024);
+#else
+  // All other platforms use their system defaults.
+  static const uint32_t kStackSize = nsIThreadManager::DEFAULT_STACK_SIZE;
+#endif
+
 private:
 
   // Returns whether there are no pools in existence at the moment.
diff --git a/dom/media/VideoUtils.h b/dom/media/VideoUtils.h
index 197061f59676..0b9452dea34b 100644
--- a/dom/media/VideoUtils.h
+++ b/dom/media/VideoUtils.h
@@ -17,11 +17,6 @@
 #include "nsSize.h"
 #include "nsRect.h"
 
-#if !(defined(XP_WIN) || defined(XP_MACOSX) || defined(LINUX)) || \
-    defined(MOZ_ASAN)
-// For MEDIA_THREAD_STACK_SIZE
-#include "nsIThreadManager.h"
-#endif
 #include "nsThreadUtils.h"
 #include "prtime.h"
 #include "AudioSampleFormat.h"
@@ -165,18 +160,6 @@ static const int32_t MAX_VIDEO_HEIGHT = 3000;
 // before being used!
 void ScaleDisplayByAspectRatio(nsIntSize& aDisplay, float aAspectRatio);
 
-// The amount of virtual memory reserved for thread stacks.
-#if defined(MOZ_ASAN)
-// Use the system default in ASAN builds, because the default is assumed to be
-// larger than the size we want to use and is hopefully sufficient for ASAN.
-#define MEDIA_THREAD_STACK_SIZE nsIThreadManager::DEFAULT_STACK_SIZE
-#elif defined(XP_WIN) || defined(XP_MACOSX) || defined(LINUX)
-#define MEDIA_THREAD_STACK_SIZE (256 * 1024)
-#else
-// All other platforms use their system defaults.
-#define MEDIA_THREAD_STACK_SIZE nsIThreadManager::DEFAULT_STACK_SIZE
-#endif
-
 // Downmix multichannel Audio samples to Stereo.
 // Input are the buffer contains multichannel data,
 // the number of channels and the number of frames.