[heap] Synchronize young generation GC with concurrent marking.

src/heap/mark-compact.cc

Index: src/heap/mark-compact.cc
diff --git a/src/heap/mark-compact.cc b/src/heap/mark-compact.cc
index a3aec5cabcd1eab36d06e11e0e266fb433cce0c2..e1e1af4b054d4e9eef6a8fe7d03c346675d166ed 100644
--- a/src/heap/mark-compact.cc
+++ b/src/heap/mark-compact.cc
@@ -2719,7 +2719,7 @@ void MinorMarkCompactCollector::EvacuateEpilogue() {
 
 void MinorMarkCompactCollector::Evacuate() {
   TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_EVACUATE);
-  Heap::RelocationLock relocation_lock(heap());
+  base::LockGuard<base::Mutex> guard(heap()->relocation_mutex());
 
   {
     TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_EVACUATE_PROLOGUE);
@@ -4085,7 +4085,7 @@ void MarkCompactCollector::Sweeper::AddSweptPageSafe(PagedSpace* space,
 
 void MarkCompactCollector::Evacuate() {
   TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_EVACUATE);
-  Heap::RelocationLock relocation_lock(heap());
+  base::LockGuard<base::Mutex> guard(heap()->relocation_mutex());
 
   {
     TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_EVACUATE_PROLOGUE);