--- a/dom/media/gstreamer/GStreamerReader.h
+++ b/dom/media/gstreamer/GStreamerReader.h
@@ -36,36 +36,36 @@ class AbstractMediaDecoder;
 class GStreamerReader : public MediaDecoderReader
 {
   typedef gfx::IntRect IntRect;
 
 public:
   explicit GStreamerReader(AbstractMediaDecoder* aDecoder);
   virtual ~GStreamerReader();
 
-  virtual nsresult Init(MediaDecoderReader* aCloneDonor);
-  virtual nsresult ResetDecode();
-  virtual bool DecodeAudioData();
+  virtual nsresult Init(MediaDecoderReader* aCloneDonor) MOZ_OVERRIDE;
+  virtual nsresult ResetDecode() MOZ_OVERRIDE;
+  virtual bool DecodeAudioData() MOZ_OVERRIDE;
   virtual bool DecodeVideoFrame(bool &aKeyframeSkip,
-                                int64_t aTimeThreshold);
+                                int64_t aTimeThreshold) MOZ_OVERRIDE;
   virtual nsresult ReadMetadata(MediaInfo* aInfo,
-                                MetadataTags** aTags);
+                                MetadataTags** aTags) MOZ_OVERRIDE;
   virtual nsRefPtr<SeekPromise>
   Seek(int64_t aTime, int64_t aEndTime) MOZ_OVERRIDE;
-  virtual nsresult GetBuffered(dom::TimeRanges* aBuffered);
+  virtual nsresult GetBuffered(dom::TimeRanges* aBuffered) MOZ_OVERRIDE;
 
   virtual void NotifyDataArrived(const char *aBuffer,
                                  uint32_t aLength,
                                  int64_t aOffset) MOZ_OVERRIDE;
 
-  virtual bool HasAudio() {
+  virtual bool HasAudio() MOZ_OVERRIDE {
     return mInfo.HasAudio();
   }
 
-  virtual bool HasVideo() {
+  virtual bool HasVideo() MOZ_OVERRIDE {
     return mInfo.HasVideo();
   }
 
   layers::ImageContainer* GetImageContainer() { return mDecoder->GetImageContainer(); }
 
   virtual bool IsMediaSeekable() MOZ_OVERRIDE;
 
 private:

--- a/dom/plugins/ipc/PluginModuleParent.h
+++ b/dom/plugins/ipc/PluginModuleParent.h
@@ -226,17 +226,17 @@ protected:
     virtual nsresult BeginUpdateBackground(NPP instance,
                                            const nsIntRect& aRect,
                                            gfxContext** aCtx) MOZ_OVERRIDE;
     virtual nsresult EndUpdateBackground(NPP instance,
                                          gfxContext* aCtx,
                                          const nsIntRect& aRect) MOZ_OVERRIDE;
 
 #if defined(XP_UNIX) && !defined(XP_MACOSX) && !defined(MOZ_WIDGET_GONK)
-    virtual nsresult NP_Initialize(NPNetscapeFuncs* bFuncs, NPPluginFuncs* pFuncs, NPError* error);
+    virtual nsresult NP_Initialize(NPNetscapeFuncs* bFuncs, NPPluginFuncs* pFuncs, NPError* error) MOZ_OVERRIDE;
 #else
     virtual nsresult NP_Initialize(NPNetscapeFuncs* bFuncs, NPError* error) MOZ_OVERRIDE;
 #endif
     virtual nsresult NP_Shutdown(NPError* error) MOZ_OVERRIDE;
 
     virtual nsresult NP_GetMIMEDescription(const char** mimeDesc) MOZ_OVERRIDE;
     virtual nsresult NP_GetValue(void *future, NPPVariable aVariable,
                                  void *aValue, NPError* error) MOZ_OVERRIDE;

--- a/gfx/thebes/gfxPangoFonts.cpp
+++ b/gfx/thebes/gfxPangoFonts.cpp
@@ -200,18 +200,18 @@ public:
     {
         cairo_font_face_set_user_data(mFontFace,
                                       &sFontEntryKey,
                                       nullptr,
                                       nullptr);
         cairo_font_face_destroy(mFontFace);
     }
 
-    virtual void ForgetHBFace();
-    virtual void ReleaseGrFace(gr_face* aFace);
+    virtual void ForgetHBFace() MOZ_OVERRIDE;
+    virtual void ReleaseGrFace(gr_face* aFace) MOZ_OVERRIDE;
 
 protected:
     virtual nsresult
     CopyFontTable(uint32_t aTableTag, FallibleTArray<uint8_t>& aBuffer) MOZ_OVERRIDE;
 
     void MaybeReleaseFTFace();
 
 private:
@@ -666,22 +666,22 @@ public:
 
 #ifdef USE_SKIA
     virtual mozilla::TemporaryRef<mozilla::gfx::GlyphRenderingOptions>
         GetGlyphRenderingOptions(const TextRunDrawParams* aRunParams = nullptr) MOZ_OVERRIDE;
 #endif
 
     // return a cloned font resized and offset to simulate sub/superscript glyphs
     virtual already_AddRefed<gfxFont>
-    GetSubSuperscriptFont(int32_t aAppUnitsPerDevPixel);
+    GetSubSuperscriptFont(int32_t aAppUnitsPerDevPixel) MOZ_OVERRIDE;
 
 protected:
     virtual already_AddRefed<gfxFont> MakeScaledFont(gfxFontStyle *aFontStyle,
                                                      gfxFloat aFontScale);
-    virtual already_AddRefed<gfxFont> GetSmallCapsFont();
+    virtual already_AddRefed<gfxFont> GetSmallCapsFont() MOZ_OVERRIDE;
 
 private:
     gfxFcFont(cairo_scaled_font_t *aCairoFont, gfxFcFontEntry *aFontEntry,
               const gfxFontStyle *aFontStyle);
 
     // key for locating a gfxFcFont corresponding to a cairo_scaled_font
     static cairo_user_data_key_t sGfxFontKey;
 };

--- a/gfx/thebes/gfxPlatform.cpp
+++ b/gfx/thebes/gfxPlatform.cpp
@@ -164,17 +164,17 @@ public:
 /// this gets called to be large - it is meant for critical errors only.
 
 class CrashStatsLogForwarder: public mozilla::gfx::LogForwarder
 {
 public:
   explicit CrashStatsLogForwarder(const char* aKey);
   virtual void Log(const std::string& aString) MOZ_OVERRIDE;
 
-  virtual std::vector<std::pair<int32_t,std::string> > StringsVectorCopy();
+  virtual std::vector<std::pair<int32_t,std::string> > StringsVectorCopy() MOZ_OVERRIDE;
 
   void SetCircularBufferSize(uint32_t aCapacity);
 
 private:
   // Helpers for the Log()
   bool UpdateStringsVector(const std::string& aString);
   void UpdateCrashReport();
 

--- a/js/src/jit/MIR.h
+++ b/js/src/jit/MIR.h
@@ -4789,18 +4789,18 @@ class MTruncateToInt32
     void computeRange(TempAllocator &alloc) MOZ_OVERRIDE;
     TruncateKind operandTruncateKind(size_t index) const MOZ_OVERRIDE;
 # ifdef DEBUG
     bool isConsistentFloat32Use(MUse *use) const MOZ_OVERRIDE {
         return true;
     }
 #endif
 
-    bool writeRecoverData(CompactBufferWriter &writer) const;
-    bool canRecoverOnBailout() const {
+    bool writeRecoverData(CompactBufferWriter &writer) const MOZ_OVERRIDE;
+    bool canRecoverOnBailout() const MOZ_OVERRIDE {
         return input()->type() < MIRType_Symbol;
     }
 
     ALLOW_CLONE(MTruncateToInt32)
 };
 
 // Converts any type to a string
 class MToString :

--- a/toolkit/system/dbus/nsNetworkManagerListener.h
+++ b/toolkit/system/dbus/nsNetworkManagerListener.h
@@ -15,19 +15,19 @@ class nsNetworkManagerListener : public 
 public:
   NS_DECL_ISUPPORTS
   NS_DECL_NSINETWORKLINKSERVICE
 
   nsNetworkManagerListener();
 
   nsresult Init();
 
-  virtual void RegisterWithConnection(DBusConnection* connection);
-  virtual void UnregisterWithConnection(DBusConnection* connection);
-  virtual bool HandleMessage(DBusMessage* msg);
+  virtual void RegisterWithConnection(DBusConnection* connection) MOZ_OVERRIDE;
+  virtual void UnregisterWithConnection(DBusConnection* connection) MOZ_OVERRIDE;
+  virtual bool HandleMessage(DBusMessage* msg) MOZ_OVERRIDE;
 
   /**
    * This gets called when NetworkManager sends us a StateChange signal,
    * or when we receive a reply to our inquiry.
    * The message contains the current NMState.
    */
   void UpdateNetworkStatus(DBusMessage* message);