make base::SharedMemoryHandle a class on POSIX.

media/base/video_frame.cc

 // 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.
 
 #include "media/base/video_frame.h"
 
 #include <algorithm>
 #include <climits>
 
 #include "base/atomic_sequence_num.h"
@@ skipping 694 matching lines @@
 
 const gpu::MailboxHolder&
 VideoFrame::mailbox_holder(size_t texture_index) const {
   DCHECK(HasTextures());
   DCHECK(IsValidPlane(texture_index, format_));
   return mailbox_holders_[texture_index];
 }
 
 base::SharedMemoryHandle VideoFrame::shared_memory_handle() const {
   DCHECK_EQ(storage_type_, STORAGE_SHMEM);
-  DCHECK(shared_memory_handle_ != base::SharedMemory::NULLHandle());
+  DCHECK(shared_memory_handle_.IsValid());
   return shared_memory_handle_;
 }
 
 size_t VideoFrame::shared_memory_offset() const {
   DCHECK_EQ(storage_type_, STORAGE_SHMEM);
-  DCHECK(shared_memory_handle_ != base::SharedMemory::NULLHandle());
+  DCHECK(shared_memory_handle_.IsValid());
   return shared_memory_offset_;
 }
 
 #if defined(OS_LINUX)
 int VideoFrame::DmabufFd(size_t plane) const {
   DCHECK_EQ(storage_type_, STORAGE_DMABUFS);
   DCHECK(IsValidPlane(plane, format_));
   return dmabuf_fds_[plane].get();
 }
 
@@ skipping 474 matching lines @@
   if (zero_initialize_memory)
     memset(data, 0, data_size);
 
   for (size_t plane = 0; plane < NumPlanes(format_); ++plane)
     data_[plane] = data + offset[plane];
 
   AddDestructionObserver(base::Bind(&base::AlignedFree, data));
 }
 
 }  // namespace media