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

components/discardable_memory/common/discardable_shared_memory_heap.h

Index: components/discardable_memory/common/discardable_shared_memory_heap.h
diff --git a/components/discardable_memory/common/discardable_shared_memory_heap.h b/components/discardable_memory/common/discardable_shared_memory_heap.h
index 2d68e253510a4d3c5efb9c8dac64b0bc26fa4365..e49ed14ac0f29a6bb488678375bd0a89de96865f 100644
--- a/components/discardable_memory/common/discardable_shared_memory_heap.h
+++ b/components/discardable_memory/common/discardable_shared_memory_heap.h
@@ -9,12 +9,12 @@
 #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"
 
@@ -166,7 +166,7 @@ class DISCARDABLE_MEMORY_EXPORT DiscardableSharedMemoryHeap {
   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;