[IndexedDB] Pool and evict leveldb iterators, to save memory

content/browser/indexed_db/leveldb/leveldb_iterator.h

Index: content/browser/indexed_db/leveldb/leveldb_iterator.h
diff --git a/content/browser/indexed_db/leveldb/leveldb_iterator.h b/content/browser/indexed_db/leveldb/leveldb_iterator.h
index d5efa4bf51951f6218d0cbcb804e282c6397b4d2..2cc80cb2937eba492020ab5c34ae480f9e398114 100644
--- a/content/browser/indexed_db/leveldb/leveldb_iterator.h
+++ b/content/browser/indexed_db/leveldb/leveldb_iterator.h
@@ -21,6 +21,8 @@ class CONTENT_EXPORT LevelDBIterator {
   virtual leveldb::Status Prev() = 0;
   virtual base::StringPiece Key() const = 0;
   virtual base::StringPiece Value() const = 0;
+  virtual void PurgeMemory(){};

[jsbell, 2017/03/22 23:55:32]

nit: space between ){

[dmurph, 2017/03/23 20:56:48]

Done.

+  virtual bool IsMemoryPurged() const;
 };
 
 }  // namespace content