make base::SharedMemoryHandle a class on POSIX.

content/child/blob_storage/blob_transport_controller_unittest.cc

 // Copyright 2015 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 "content/child/blob_storage/blob_transport_controller.h"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <tuple>
 
@@ skipping 282 matching lines @@
 
   // Request for all data in shared memory
   requests.push_back(
       BlobItemBytesRequest::CreateSharedMemoryRequest(0, 1, 0, 11, 0, 0));
   requests.push_back(
       BlobItemBytesRequest::CreateSharedMemoryRequest(1, 3, 0, 6, 0, 11));
   base::SharedMemory memory;
   memory.CreateAnonymous(11 + 6);
   base::SharedMemoryHandle handle =
       base::SharedMemory::DuplicateHandle(memory.handle());
-  CHECK(base::SharedMemory::NULLHandle() != handle);
+  CHECK(handle.IsValid());
   memory_handles.push_back(handle);
 
   OnMemoryRequest(holder, kBlobUUID, requests, &memory_handles, file_handles);
   std::vector<storage::BlobItemBytesResponse> expected;
   expected.push_back(BlobItemBytesResponse(0));
   expected.push_back(BlobItemBytesResponse(1));
   ExpectMemoryResponses(kBlobUUID, expected);
   std::string expected_memory = "HelloHello2Hello3";
   memory.Map(11 + 6);
   const char* mem_location = static_cast<const char*>(memory.memory());
@@ skipping 156 matching lines @@
   EXPECT_FALSE(main_thread_runner_->HasPendingTask());
 
   // Finish the second one.
   holder->OnBlobFinalStatus(kBlob2UUID, BlobStatus::DONE);
   EXPECT_FALSE(holder->IsTransporting(kBlob2UUID));
   EXPECT_TRUE(main_thread_runner_->HasPendingTask());
   main_thread_runner_->ClearPendingTasks();
 }
 
 }  // namespace content