Update more platform classes to use OVERRIDE / FINAL when needed

Source/platform/audio/MultiChannelResampler.cpp

Index: Source/platform/audio/MultiChannelResampler.cpp
diff --git a/Source/platform/audio/MultiChannelResampler.cpp b/Source/platform/audio/MultiChannelResampler.cpp
index 82f291a9bf11e5c9fb3b020272472550fb208146..827506f2ade5f16d009eef788177856f0174a16d 100644
--- a/Source/platform/audio/MultiChannelResampler.cpp
+++ b/Source/platform/audio/MultiChannelResampler.cpp
@@ -41,7 +41,7 @@ namespace {
 // ChannelProvider provides a single channel of audio data (one channel at a time) for each channel
 // of data provided to us in a multi-channel provider.
 
-class ChannelProvider : public AudioSourceProvider {
+class ChannelProvider FINAL : public AudioSourceProvider {
 public:
     ChannelProvider(AudioSourceProvider* multiChannelProvider, unsigned numberOfChannels)
         : m_multiChannelProvider(multiChannelProvider)
@@ -53,7 +53,7 @@ public:
 
     // provideInput() will be called once for each channel, starting with the first channel.
     // Each time it's called, it will provide the next channel of data.
-    virtual void provideInput(AudioBus* bus, size_t framesToProcess)
+    virtual void provideInput(AudioBus* bus, size_t framesToProcess) OVERRIDE
     {
         bool isBusGood = bus && bus->numberOfChannels() == 1;
         ASSERT(isBusGood);