Revert r95841 due to failing media_unittests on linux_shared bot.

media/base/buffers.h

Index: media/base/buffers.h
===================================================================
--- media/base/buffers.h	(revision 95843)
+++ media/base/buffers.h	(working copy)
@@ -30,15 +30,13 @@
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/time.h"
-#include "media/base/media_export.h"
 
 namespace media {
 
 // Indicates an invalid or missing timestamp.
-MEDIA_EXPORT extern const base::TimeDelta kNoTimestamp;
+extern const base::TimeDelta kNoTimestamp;
 
-class MEDIA_EXPORT StreamSample
-    : public base::RefCountedThreadSafe<StreamSample> {
+class StreamSample : public base::RefCountedThreadSafe<StreamSample> {
  public:
   // Returns the timestamp of this buffer in microseconds.
   base::TimeDelta GetTimestamp() const {
@@ -78,7 +76,7 @@
 };
 
 
-class MEDIA_EXPORT Buffer : public StreamSample {
+class Buffer : public StreamSample {
  public:
   // Returns a read only pointer to the buffer data.
   virtual const uint8* GetData() const = 0;