Revert 99236 - Very short-term change: while working on proper long-term solution,

media/audio/audio_util.cc

Index: media/audio/audio_util.cc
===================================================================
--- media/audio/audio_util.cc	(revision 99444)
+++ media/audio/audio_util.cc	(working copy)
@@ -21,8 +21,6 @@
 
 using base::subtle::Atomic32;
 
-const uint32 kUnknownDataSize = static_cast<uint32>(-1);
-
 namespace media {
 
 // TODO(fbarchard): Convert to intrinsics for better efficiency.
@@ -259,7 +257,7 @@
   char* ptr = static_cast<char*>(shared_memory->memory()) + shared_memory_size;
   DCHECK_EQ(0u, reinterpret_cast<size_t>(ptr) & 3);
 
-  // Actual data size stored at the end of the buffer.
+  // Actual data size stored in the beginning of the buffer.
   uint32 actual_data_size =
       base::subtle::Acquire_Load(reinterpret_cast<volatile Atomic32*>(ptr));
   return std::min(actual_data_size, shared_memory_size);
@@ -271,25 +269,9 @@
   char* ptr = static_cast<char*>(shared_memory->memory()) + shared_memory_size;
   DCHECK_EQ(0u, reinterpret_cast<size_t>(ptr) & 3);
 
-  // Set actual data size in at the end of the buffer.
+  // Set actual data size in the beginning of the buffer.
   base::subtle::Release_Store(reinterpret_cast<volatile Atomic32*>(ptr),
                               actual_data_size);
 }
 
-void SetUnknownDataSize(base::SharedMemory* shared_memory,
-                        uint32 shared_memory_size) {
-  SetActualDataSizeInBytes(shared_memory, shared_memory_size, kUnknownDataSize);
-}
-
-bool IsUnknownDataSize(base::SharedMemory* shared_memory,
-                       uint32 shared_memory_size) {
-  char* ptr = static_cast<char*>(shared_memory->memory()) + shared_memory_size;
-  DCHECK_EQ(0u, reinterpret_cast<size_t>(ptr) & 3);
-
-  // Actual data size stored at the end of the buffer.
-  uint32 actual_data_size =
-      base::subtle::Acquire_Load(reinterpret_cast<volatile Atomic32*>(ptr));
-  return actual_data_size == kUnknownDataSize;
-}
-
 }  // namespace media