[heap] Take page lock when scavenging old to new references in Scavenger.

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 7dfdb9c8d25a01cf713e0f5af5d87a4336b31285..312998e32c2557f9e8fcbf1e6b7b7e7dacb5887a 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -1723,12 +1723,12 @@ void Heap::Scavenge() {
   {
     // Copy objects reachable from the old generation.
     TRACE_GC(tracer(), GCTracer::Scope::SCAVENGER_OLD_TO_NEW_POINTERS);
-    RememberedSet<OLD_TO_NEW>::Iterate(this, [this](Address addr) {
+    RememberedSet<OLD_TO_NEW>::Iterate(this, true, [this](Address addr) {

[ulan, 2017/03/30 12:04:18]

Let's use enum here as we usually do.

       return Scavenger::CheckAndScavengeObject(this, addr);
     });
 
     RememberedSet<OLD_TO_NEW>::IterateTyped(
-        this, [this](SlotType type, Address host_addr, Address addr) {
+        this, true, [this](SlotType type, Address host_addr, Address addr) {
           return UpdateTypedSlotHelper::UpdateTypedSlot(
               isolate(), type, addr, [this](Object** addr) {
                 // We expect that objects referenced by code are long living.