Enable AudioDecoder unit tests on Android

media/base/audio_hash.h

Index: media/base/audio_hash.h
diff --git a/media/base/audio_hash.h b/media/base/audio_hash.h
index 83ee901d3c97a29d0a703fd98a446f5c3d4f9e94..5ac1aa267b716565ccdd892719e10c3b377716fd 100644
--- a/media/base/audio_hash.h
+++ b/media/base/audio_hash.h
@@ -43,6 +43,11 @@ class MEDIA_EXPORT AudioHash {
   // Return a string representation of the current hash.
   std::string ToString() const;
 
+  // Compare with another hash value given as string representation.
+  // Returns true if for every bucket the difference between this and
+  // other is less than tolerance.
+  bool IsEquivalent(const std::string& other, double tolerance) const;
+
  private:
   // Storage for the audio hash.  The number of buckets controls the importance
   // of position in the hash.  A higher number reduces the chance of false