Pull up mBufferSize from RecordThread to ThreadBase

Now both playback and record threads have a HAL buffer size for fast
tracks, and a potentially larger-sized buffer for normal tracks.

Change-Id: I6f57b85ecece3cbd4e9e64b8c41c3352f7656912
diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index aa04fd4..99c42fc 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -270,6 +270,7 @@
                 uint32_t                mChannelCount;
                 size_t                  mFrameSize;
                 audio_format_t          mFormat;
+                size_t                  mBufferSize;       // HAL buffer size for read() or write()
 
                 // Parameter sequence by client: binder thread calling setParameters():
                 //  1. Lock mLock
@@ -902,7 +903,6 @@
             int32_t                             *mRsmpOutBuffer;
             int16_t                             *mRsmpInBuffer; // [mFrameCount * mChannelCount]
             size_t                              mRsmpInIndex;
-            size_t                              mBufferSize;    // stream buffer size for read()
             const uint32_t                      mReqChannelCount;
             const uint32_t                      mReqSampleRate;
             ssize_t                             mBytesRead;