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

components/discardable_memory/common/discardable_shared_memory_heap.cc

Index: components/discardable_memory/common/discardable_shared_memory_heap.cc
diff --git a/components/discardable_memory/common/discardable_shared_memory_heap.cc b/components/discardable_memory/common/discardable_shared_memory_heap.cc
index 7eacbeeec77e03d56bbe2efe6edd459c30cdc4d1..0bad4cf2532880ffa3dc4223b68b2d1cb4f638a6 100644
--- a/components/discardable_memory/common/discardable_shared_memory_heap.cc
+++ b/components/discardable_memory/common/discardable_shared_memory_heap.cc
@@ -131,7 +131,7 @@ DiscardableSharedMemoryHeap::Grow(
   num_blocks_ += span->length_;
 
   // Start tracking if segment is resident by adding it to |memory_segments_|.
-  memory_segments_.push_back(base::MakeUnique<ScopedMemorySegment>(
+  memory_segments_.push_back(new ScopedMemorySegment(
       this, std::move(shared_memory), size, id, deleted_callback));
 
   return span;
@@ -226,10 +226,9 @@ void DiscardableSharedMemoryHeap::ReleaseFreeMemory() {
   // Erase all free segments after rearranging the segments in such a way
   // that used segments precede all free segments.
   memory_segments_.erase(
-      std::partition(memory_segments_.begin(), memory_segments_.end(),
-                     [](const std::unique_ptr<ScopedMemorySegment>& segment) {
-                       return segment->IsUsed();
-                     }),
+      std::partition(
+          memory_segments_.begin(), memory_segments_.end(),
+          [](const ScopedMemorySegment* segment) { return segment->IsUsed(); }),
       memory_segments_.end());
 }
 
@@ -238,7 +237,7 @@ void DiscardableSharedMemoryHeap::ReleasePurgedMemory() {
   // that resident segments precede all purged segments.
   memory_segments_.erase(
       std::partition(memory_segments_.begin(), memory_segments_.end(),
-                     [](const std::unique_ptr<ScopedMemorySegment>& segment) {
+                     [](const ScopedMemorySegment* segment) {
                        return segment->IsResident();
                      }),
       memory_segments_.end());
@@ -255,7 +254,7 @@ size_t DiscardableSharedMemoryHeap::GetSizeOfFreeLists() const {
 bool DiscardableSharedMemoryHeap::OnMemoryDump(
     base::trace_event::ProcessMemoryDump* pmd) {
   std::for_each(memory_segments_.begin(), memory_segments_.end(),
-                [pmd](const std::unique_ptr<ScopedMemorySegment>& segment) {
+                [pmd](const ScopedMemorySegment* segment) {
                   segment->OnMemoryDump(pmd);
                 });
   return true;
@@ -467,9 +466,9 @@ DiscardableSharedMemoryHeap::CreateMemoryAllocatorDump(
     return dump;
   }
 
-  auto it =
+  ScopedVector<ScopedMemorySegment>::const_iterator it =
       std::find_if(memory_segments_.begin(), memory_segments_.end(),
-                   [span](const std::unique_ptr<ScopedMemorySegment>& segment) {
+                   [span](const ScopedMemorySegment* segment) {
                      return segment->ContainsSpan(span);
                    });
   DCHECK(it != memory_segments_.end());