Mark fields const if only set in constructor

Change-Id: Iacd06bb9efaf708cf965033be1f2297b58f7f75c
diff --git a/services/audioflinger/AudioResampler.h b/services/audioflinger/AudioResampler.h
index ee171ff..c23016e 100644
--- a/services/audioflinger/AudioResampler.h
+++ b/services/audioflinger/AudioResampler.h
@@ -72,9 +72,9 @@
     AudioResampler(const AudioResampler&);
     AudioResampler& operator=(const AudioResampler&);
 
-    int32_t mBitDepth;
-    int32_t mChannelCount;
-    int32_t mSampleRate;
+    const int32_t mBitDepth;
+    const int32_t mChannelCount;
+    const int32_t mSampleRate;
     int32_t mInSampleRate;
     AudioBufferProvider::Buffer mBuffer;
     union {