Get rid of base::SharedMemory::NULLHandle();

ui/surface/transport_dib.h

 // Copyright (c) 2012 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 UI_SURFACE_TRANSPORT_DIB_H_
 #define UI_SURFACE_TRANSPORT_DIB_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 16 matching lines @@
 // between renderer and plugin processes.
 // -----------------------------------------------------------------------------
 class SURFACE_EXPORT TransportDIB {
  public:
   ~TransportDIB();
 
 // A Handle is the type which can be sent over the wire so that the remote
 // side can map the transport DIB.
   typedef base::SharedMemoryHandle Handle;
 
-  // Returns a default, invalid handle, that is meant to indicate a missing
-  // Transport DIB.
-  static Handle DefaultHandleValue() {
-    return base::SharedMemory::NULLHandle();
-  }
-
   // Create a new TransportDIB, returning NULL on failure.
   //
   // The size is the minimum size in bytes of the memory backing the transport
   // DIB (we may actually allocate more than that to give us better reuse when
   // cached).
   //
   // The sequence number is used to uniquely identify the transport DIB. It
   // should be unique for all transport DIBs ever created in the same
   // renderer.
   static TransportDIB* Create(size_t size, uint32_t sequence_num);
@@ skipping 45 matching lines @@
 
   explicit TransportDIB(base::SharedMemoryHandle dib);
   base::SharedMemory shared_memory_;
   uint32_t sequence_num_;
   size_t size_;  // length, in bytes
 
   DISALLOW_COPY_AND_ASSIGN(TransportDIB);
 };
 
 #endif  // UI_SURFACE_TRANSPORT_DIB_H_