Remove calls to heapsize (#10432)

* update memorydb trait
* use malloc_size_of instead of heapsize_of
* use jemalloc as default allocator for parity client.

ethcore/sync/src/block_sync.rs

@@ -20,7 +20,7 @@
 
 use std::collections::{HashSet, VecDeque};
 use std::cmp;
-use heapsize::HeapSizeOf;
+use parity_util_mem::MallocSizeOf;
 use ethereum_types::H256;
 use rlp::{self, Rlp};
 use types::BlockNumber;
@@ -60,7 +60,7 @@ macro_rules! debug_sync {
 	};
 }
 
-#[derive(Copy, Clone, Eq, PartialEq, Debug)]
+#[derive(Copy, Clone, Eq, PartialEq, Debug, MallocSizeOf)]
 /// Downloader state
 pub enum State {
 	/// No active downloads.
@@ -113,6 +113,7 @@ impl From<rlp::DecoderError> for BlockDownloaderImportError {
 
 /// Block downloader strategy.
 /// Manages state and block data for a block download process.
+#[derive(MallocSizeOf)]
 pub struct BlockDownloader {
 	/// Which set of blocks to download
 	block_set: BlockSet,
@@ -223,11 +224,6 @@ impl BlockDownloader {
 		self.state = State::Blocks;
 	}
 
-	/// Returns used heap memory size.
-	pub fn heap_size(&self) -> usize {
-		self.blocks.heap_size() + self.round_parents.heap_size_of_children()
-	}
-
 	/// Returns best imported block number.
 	pub fn last_imported_block_number(&self) -> BlockNumber {
 		self.last_imported_block