Remove AudioBuffer::set_duration(), instead base on frames.

content/renderer/pepper/content_decryptor_delegate.cc

Index: content/renderer/pepper/content_decryptor_delegate.cc
diff --git a/content/renderer/pepper/content_decryptor_delegate.cc b/content/renderer/pepper/content_decryptor_delegate.cc
index a10b741864515479e92f5ed23d65eb3936066c36..a36cf6f353965d041c421e3f538bd81c708c6b0b 100644
--- a/content/renderer/pepper/content_decryptor_delegate.cc
+++ b/content/renderer/pepper/content_decryptor_delegate.cc
@@ -1026,9 +1026,7 @@ bool ContentDecryptorDelegate::DeserializeAudioFrames(
         audio_samples_per_second_,
         frame_count,
         &channel_ptrs[0],
-        base::TimeDelta::FromMicroseconds(timestamp),
-        base::TimeDelta::FromMicroseconds(audio_samples_per_second_ /
-                                          frame_count));
+        base::TimeDelta::FromMicroseconds(timestamp));
     frames->push_back(frame);
 
     cur += frame_size;