diff --git a/content/media/wmf/WMFReader.cpp b/content/media/wmf/WMFReader.cpp
index 34450a69bccd..4c23282874c5 100644
--- a/content/media/wmf/WMFReader.cpp
+++ b/content/media/wmf/WMFReader.cpp
@@ -51,8 +51,8 @@ WMFReader::WMFReader(AbstractMediaDecoder* aDecoder)
     mHasAudio(false),
     mHasVideo(false),
     mCanSeek(false),
-    mIsMP3Enabled(WMFDecoder::IsMP3Supported()),
-    mUseHwAccel(false)
+    mUseHwAccel(false),
+    mIsMP3Enabled(WMFDecoder::IsMP3Supported())
 {
   NS_ASSERTION(NS_IsMainThread(), "Must be on main thread.");
   MOZ_COUNT_CTOR(WMFReader);
@@ -789,7 +789,6 @@ WMFReader::CreateD3DVideoFrame(IMFSample* aSample,
   *aOutVideoData = nullptr;
   HRESULT hr;
 
-  ImageFormat format = D3D9_RGB32_TEXTURE;
   nsRefPtr<Image> image;
   hr = mDXVA2Manager->CopyToImage(aSample,
                                   nsIntSize(mPictureRegion.width, mPictureRegion.height),
diff --git a/content/media/wmf/WMFSourceReaderCallback.cpp b/content/media/wmf/WMFSourceReaderCallback.cpp
index 9aee5f56c62c..5164eb5c6341 100644
--- a/content/media/wmf/WMFSourceReaderCallback.cpp
+++ b/content/media/wmf/WMFSourceReaderCallback.cpp
@@ -37,12 +37,12 @@ NS_IMPL_THREADSAFE_ADDREF(WMFSourceReaderCallback)
 NS_IMPL_THREADSAFE_RELEASE(WMFSourceReaderCallback)
 
 WMFSourceReaderCallback::WMFSourceReaderCallback()
-  : mResultStatus(S_OK)
+  : mMonitor("WMFSourceReaderCallback")
+  , mResultStatus(S_OK)
   , mStreamFlags(0)
   , mTimestamp(0)
   , mSample(nullptr)
   , mReadFinished(false)
-  , mMonitor("WMFSourceReaderCallback")
 {
 #ifdef PR_LOGGING
   if (!gWMFSourceReaderCallbackLog) {
diff --git a/content/media/wmf/WMFSourceReaderCallback.h b/content/media/wmf/WMFSourceReaderCallback.h
index 752f9ecdc73e..43feb091656f 100644
--- a/content/media/wmf/WMFSourceReaderCallback.h
+++ b/content/media/wmf/WMFSourceReaderCallback.h
@@ -19,7 +19,7 @@ namespace mozilla {
 // WMFByteStream's underlying MediaResource is closed. This ensures that
 // the decode threads don't get stuck in a synchronous ReadSample() call
 // when the MediaResource is unexpectedly shutdown.
-class WMFSourceReaderCallback : public IMFSourceReaderCallback
+class WMFSourceReaderCallback MOZ_FINAL : public IMFSourceReaderCallback
 {
 public:
   WMFSourceReaderCallback();