av: Fix build in ISO C++11 mode

Change-Id: I461d8ce5b24afedee245a6441b600df286c76b63
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
diff --git a/services/audioflinger/AudioResampler.h b/services/audioflinger/AudioResampler.h
index 2b8694f..cb0259a 100644
--- a/services/audioflinger/AudioResampler.h
+++ b/services/audioflinger/AudioResampler.h
@@ -22,6 +22,10 @@
 
 #include <media/AudioBufferProvider.h>
 
+#if __cplusplus < 201103L && !defined(__GXX_EXPERIMENTAL_CXX0X__) && !defined(constexpr)
+#define constexpr const
+#endif
+
 namespace android {
 // ----------------------------------------------------------------------------
 
@@ -66,13 +70,13 @@
 
 protected:
     // number of bits for phase fraction - 30 bits allows nearly 2x downsampling
-    static const int kNumPhaseBits = 30;
+    static constexpr int kNumPhaseBits = 30;
 
     // phase mask for fraction
-    static const uint32_t kPhaseMask = (1LU<<kNumPhaseBits)-1;
+    static constexpr uint32_t kPhaseMask = (1LU<<kNumPhaseBits)-1;
 
     // multiplier to calculate fixed point phase increment
-    static const double kPhaseMultiplier = 1L << kNumPhaseBits;
+    static constexpr double kPhaseMultiplier = 1L << kNumPhaseBits;
 
     AudioResampler(int bitDepth, int inChannelCount, int32_t sampleRate, src_quality quality);