Revert "Remove scopedvector in //components/discardable_memory/"

components/discardable_memory/common/discardable_shared_memory_heap.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 COMPONENTS_DISCARDABLE_MEMORY_COMMON_DISCARDABLE_SHARED_MEMORY_HEAP_H_
 #define COMPONENTS_DISCARDABLE_MEMORY_COMMON_DISCARDABLE_SHARED_MEMORY_HEAP_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
-#include <vector>
 
 #include "base/callback.h"
 #include "base/containers/hash_tables.h"
 #include "base/containers/linked_list.h"
 #include "base/macros.h"
+#include "base/memory/scoped_vector.h"
 #include "base/trace_event/process_memory_dump.h"
 #include "components/discardable_memory/common/discardable_memory_export.h"
 
 namespace base {
 class DiscardableSharedMemory;
 }
 
 namespace discardable_memory {
 
 // Implements a heap of discardable shared memory. An array of free lists
@@ skipping 131 matching lines @@
   void OnMemoryDump(const base::DiscardableSharedMemory* shared_memory,
                     size_t size,
                     int32_t segment_id,
                     base::trace_event::ProcessMemoryDump* pmd);
 
   size_t block_size_;
   size_t num_blocks_;
   size_t num_free_blocks_;
 
   // Vector of memory segments.
-  std::vector<std::unique_ptr<ScopedMemorySegment>> memory_segments_;
+  ScopedVector<ScopedMemorySegment> memory_segments_;
 
   // Mapping from first/last block of span to Span instance.
   typedef base::hash_map<size_t, Span*> SpanMap;
   SpanMap spans_;
 
   // Array of linked-lists with free discardable memory regions. For i < 256,
   // where the 1st entry is located at index 0 of the array, the kth entry
   // is a free list of runs that consist of k blocks. The 256th entry is a
   // free list of runs that have length >= 256 blocks.
   base::LinkedList<Span> free_spans_[256];
 
   DISALLOW_COPY_AND_ASSIGN(DiscardableSharedMemoryHeap);
 };
 
 }  // namespace discardable_memory
 
 #endif  // COMPONENTS_DISCARDABLE_MEMORY_COMMON_DISCARDABLE_SHARED_MEMORY_HEAP_H_