[Fetch API] Remove DrainingBuffer.

public/platform/WebDataConsumerHandle.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WebDataConsumerHandle_h
 #define WebDataConsumerHandle_h
 
 #include <stddef.h>
 
 #if INSIDE_BLINK
@@ skipping 24 matching lines @@
     enum Result {
         Ok,
         Done,
         Busy,
         ShouldWait,
         ResourceExhausted,
         UnexpectedError,
     };
 
     // Client gets notification from the pipe.
-    class Client {
+    class BLINK_PLATFORM_EXPORT Client {
     public:
         virtual ~Client() { }
         // The associated handle gets readable. This function will be called
         // when the associated reader was waiting but is not waiting any more.
         // This means this function can be called when handle gets errored or
         // closed. This also means that this function will not be called even
         // when some data arrives if the handle already has non-empty readable
         // data.
         // It is not guaranteed that the handle is not waiting when this
         // function is called, i.e. it can be called more than needed.
@@ skipping 70 matching lines @@
     virtual Reader* obtainReaderInternal(Client* client)
     {
         BLINK_ASSERT_NOT_REACHED();
         return nullptr;
     }
 };
 
 } // namespace blink
 
 #endif // WebDataConsumerHandle_h