Bug 1555550 - Use decommitAllArenas which also updates bookkeeping r=jonco

Differential Revision: https://phabricator.services.mozilla.com/D33111

--HG--
extra : moz-landing-system : lando

js/src/gc/Heap.h

@@ -789,6 +789,7 @@ struct Chunk {
   void recycleArena(Arena* arena, SortedArenaList& dest, size_t thingsPerArena);
 
   MOZ_MUST_USE bool decommitOneFreeArena(JSRuntime* rt, AutoLockGC& lock);
+  void decommitAllArenas();
 
   // This will decommit each unused not-already decommitted arena. It performs a
   // system call for each arena but is only used during OOM.
@@ -798,8 +799,6 @@ struct Chunk {
   void init(JSRuntime* rt);
 
  private:
-  void decommitAllArenas();
-
   /* Search for a decommitted arena to allocate. */
   unsigned findDecommittedArenaOffset();
   Arena* fetchNextDecommittedArena();

js/src/gc/Nursery.cpp

@@ -133,7 +133,7 @@ void js::NurseryDecommitChunksTask::run() {
 }
 
 void js::NurseryDecommitChunksTask::decommitChunk(Chunk* chunk) {
-  MarkPagesUnused(&chunk->arenas[0], ArenaSize * ArenasPerChunk);
+  chunk->decommitAllArenas();
   {
     AutoLockGC lock(runtime());
     runtime()->gc.recycleChunk(chunk, lock);