Update V8 to r5388 as required by WebKit r66666

Change-Id: Ib3c42e9b7226d22c65c7077c543fe31afe62a318
diff --git a/src/heap.cc b/src/heap.cc
index ff92384..443c926 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -104,6 +104,7 @@
 
 GCCallback Heap::global_gc_prologue_callback_ = NULL;
 GCCallback Heap::global_gc_epilogue_callback_ = NULL;
+HeapObjectCallback Heap::gc_safe_size_of_old_object_ = NULL;
 
 // Variables set based on semispace_size_ and old_generation_size_ in
 // ConfigureHeap.
@@ -193,6 +194,33 @@
 }
 
 
+int Heap::GcSafeSizeOfOldObject(HeapObject* object) {
+  ASSERT(!Heap::InNewSpace(object));  // Code only works for old objects.
+  ASSERT(!MarkCompactCollector::are_map_pointers_encoded());
+  MapWord map_word = object->map_word();
+  map_word.ClearMark();
+  map_word.ClearOverflow();
+  return object->SizeFromMap(map_word.ToMap());
+}
+
+
+int Heap::GcSafeSizeOfOldObjectWithEncodedMap(HeapObject* object) {
+  ASSERT(!Heap::InNewSpace(object));  // Code only works for old objects.
+  ASSERT(MarkCompactCollector::are_map_pointers_encoded());
+  uint32_t marker = Memory::uint32_at(object->address());
+  if (marker == MarkCompactCollector::kSingleFreeEncoding) {
+    return kIntSize;
+  } else if (marker == MarkCompactCollector::kMultiFreeEncoding) {
+    return Memory::int_at(object->address() + kIntSize);
+  } else {
+    MapWord map_word = object->map_word();
+    Address map_address = map_word.DecodeMapAddress(Heap::map_space());
+    Map* map = reinterpret_cast<Map*>(HeapObject::FromAddress(map_address));
+    return object->SizeFromMap(map);
+  }
+}
+
+
 GarbageCollector Heap::SelectGarbageCollector(AllocationSpace space) {
   // Is global GC requested?
   if (space != NEW_SPACE || FLAG_gc_global) {
@@ -540,6 +568,13 @@
 
   // Committing memory to from space failed.
   // Try shrinking and try again.
+  PagedSpaces spaces;
+  for (PagedSpace* space = spaces.next();
+       space != NULL;
+       space = spaces.next()) {
+    space->RelinkPageListInChunkOrder(true);
+  }
+
   Shrink();
   if (new_space_.CommitFromSpaceIfNeeded()) return;
 
@@ -571,6 +606,22 @@
 }
 
 
+class ClearThreadNormalizedMapCachesVisitor: public ThreadVisitor {
+  virtual void VisitThread(ThreadLocalTop* top) {
+    Context* context = top->context_;
+    if (context == NULL) return;
+    context->global()->global_context()->normalized_map_cache()->Clear();
+  }
+};
+
+
+void Heap::ClearNormalizedMapCaches() {
+  if (Bootstrapper::IsActive()) return;
+  ClearThreadNormalizedMapCachesVisitor visitor;
+  ThreadManager::IterateArchivedThreads(&visitor);
+}
+
+
 #ifdef DEBUG
 
 enum PageWatermarkValidity {
@@ -726,8 +777,6 @@
 
   MarkCompactCollector::CollectGarbage();
 
-  MarkCompactEpilogue(is_compacting);
-
   LOG(ResourceEvent("markcompact", "end"));
 
   gc_state_ = NOT_IN_GC;
@@ -749,18 +798,11 @@
 
   CompilationCache::MarkCompactPrologue();
 
-  Top::MarkCompactPrologue(is_compacting);
-  ThreadManager::MarkCompactPrologue(is_compacting);
-
   CompletelyClearInstanceofCache();
 
   if (is_compacting) FlushNumberStringCache();
-}
 
-
-void Heap::MarkCompactEpilogue(bool is_compacting) {
-  Top::MarkCompactEpilogue(is_compacting);
-  ThreadManager::MarkCompactEpilogue(is_compacting);
+  ClearNormalizedMapCaches();
 }
 
 
@@ -4031,6 +4073,8 @@
   NewSpaceScavenger::Initialize();
   MarkCompactCollector::Initialize();
 
+  MarkMapPointersAsEncoded(false);
+
   // Setup memory allocator and reserve a chunk of memory for new
   // space.  The chunk is double the size of the requested reserved
   // new space size to ensure that we can find a pair of semispaces that