Revert "[heap] Move pointers updating to ItemParallelJob"

This reverts commit 81d3427b.

Reason for revert: Several gc related failures, e.g.:
https://build.chromium.org/p/client.v8/builders/V8%20Mac%20GC%20Stress/builds/13488

Original change's description:
> [heap] Move pointers updating to ItemParallelJob
> 
> Furthermore avoid lock-step between pointer updating phases as they
> should execute in parallel without synchronization restrictions.
> 
> Bug: chromium:726040
> Change-Id: I26ce0d1f2a4637ff5610cae556113e3d736788e2
> Reviewed-on: https://chromium-review.googlesource.com/518103
> Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
> Reviewed-by: Hannes Payer <hpayer@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#45574}

NOPRESUBMIT=true
NOTRY=true
NOTREECHECKS=true

TBR=ulan@chromium.org,hpayer@chromium.org,mlippautz@chromium.org
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:726040

Change-Id: I60860aef390605d07bc520141cab9d5be9b712b3
Reviewed-on: https://chromium-review.googlesource.com/518106
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45575}

src/heap/gc-tracer.cc

@@ -538,8 +538,10 @@ void GCTracer::PrintNVP() const {
           "evacuate=%.2f "
           "evacuate.copy=%.2f "
           "evacuate.update_pointers=%.2f "
-          "evacuate.update_pointers.to_new_roots=%.2f "
-          "evacuate.update_pointers.slots=%.2f "
+          "evacuate.update_pointers.to_new=%.2f "
+          "evacuate.update_pointers.to_new.tospace=%.2f "
+          "evacuate.update_pointers.to_new.roots=%.2f "
+          "evacuate.update_pointers.to_new.old=%.2f "
           "update_marking_deque=%.2f "
           "reset_liveness=%.2f\n",
           duration, spent_in_mutator, "mmc", current_.reduce_memory,
@@ -556,9 +558,12 @@ void GCTracer::PrintNVP() const {
           current_.scopes[Scope::MINOR_MC_EVACUATE],
           current_.scopes[Scope::MINOR_MC_EVACUATE_COPY],
           current_.scopes[Scope::MINOR_MC_EVACUATE_UPDATE_POINTERS],
+          current_.scopes[Scope::MINOR_MC_EVACUATE_UPDATE_POINTERS_TO_NEW],
+          current_
+              .scopes[Scope::MINOR_MC_EVACUATE_UPDATE_POINTERS_TO_NEW_TOSPACE],
           current_
               .scopes[Scope::MINOR_MC_EVACUATE_UPDATE_POINTERS_TO_NEW_ROOTS],
-          current_.scopes[Scope::MINOR_MC_EVACUATE_UPDATE_POINTERS_SLOTS],
+          current_.scopes[Scope::MINOR_MC_EVACUATE_UPDATE_POINTERS_TO_NEW_OLD],
           current_.scopes[Scope::MINOR_MC_MARKING_DEQUE],
           current_.scopes[Scope::MINOR_MC_RESET_LIVENESS]);
       break;
@@ -593,8 +598,8 @@ void GCTracer::PrintNVP() const {
           "evacuate.epilogue=%.1f "
           "evacuate.rebalance=%.1f "
           "evacuate.update_pointers=%.1f "
-          "evacuate.update_pointers.to_new_roots=%.1f "
-          "evacuate.update_pointers.slots=%.1f "
+          "evacuate.update_pointers.to_evacuated=%.1f "
+          "evacuate.update_pointers.to_new=%.1f "
           "evacuate.update_pointers.weak=%.1f "
           "finish=%.1f "
           "mark=%.1f "
@@ -677,8 +682,8 @@ void GCTracer::PrintNVP() const {
           current_.scopes[Scope::MC_EVACUATE_EPILOGUE],
           current_.scopes[Scope::MC_EVACUATE_REBALANCE],
           current_.scopes[Scope::MC_EVACUATE_UPDATE_POINTERS],
-          current_.scopes[Scope::MC_EVACUATE_UPDATE_POINTERS_TO_NEW_ROOTS],
-          current_.scopes[Scope::MC_EVACUATE_UPDATE_POINTERS_SLOTS],
+          current_.scopes[Scope::MC_EVACUATE_UPDATE_POINTERS_TO_EVACUATED],
+          current_.scopes[Scope::MC_EVACUATE_UPDATE_POINTERS_TO_NEW],
           current_.scopes[Scope::MC_EVACUATE_UPDATE_POINTERS_WEAK],
           current_.scopes[Scope::MC_FINISH], current_.scopes[Scope::MC_MARK],
           current_.scopes[Scope::MC_MARK_FINISH_INCREMENTAL],

src/heap/gc-tracer.h

@@ -60,8 +60,8 @@ enum ScavengeSpeedMode { kForAllObjects, kForSurvivedObjects };
   F(MC_EVACUATE_PROLOGUE)                             \
   F(MC_EVACUATE_REBALANCE)                            \
   F(MC_EVACUATE_UPDATE_POINTERS)                      \
-  F(MC_EVACUATE_UPDATE_POINTERS_SLOTS)              \
-  F(MC_EVACUATE_UPDATE_POINTERS_TO_NEW_ROOTS)       \
+  F(MC_EVACUATE_UPDATE_POINTERS_TO_EVACUATED)         \
+  F(MC_EVACUATE_UPDATE_POINTERS_TO_NEW)               \
   F(MC_EVACUATE_UPDATE_POINTERS_WEAK)                 \
   F(MC_FINISH)                                        \
   F(MC_MARK)                                          \
@@ -91,8 +91,10 @@ enum ScavengeSpeedMode { kForAllObjects, kForSurvivedObjects };
   F(MINOR_MC_EVACUATE_PROLOGUE)                       \
   F(MINOR_MC_EVACUATE_REBALANCE)                      \
   F(MINOR_MC_EVACUATE_UPDATE_POINTERS)                \
-  F(MINOR_MC_EVACUATE_UPDATE_POINTERS_SLOTS)        \
+  F(MINOR_MC_EVACUATE_UPDATE_POINTERS_TO_NEW)         \
   F(MINOR_MC_EVACUATE_UPDATE_POINTERS_TO_NEW_ROOTS)   \
+  F(MINOR_MC_EVACUATE_UPDATE_POINTERS_TO_NEW_TOSPACE) \
+  F(MINOR_MC_EVACUATE_UPDATE_POINTERS_TO_NEW_OLD)     \
   F(MINOR_MC_EVACUATE_UPDATE_POINTERS_WEAK)           \
   F(MINOR_MC_MARK)                                    \
   F(MINOR_MC_MARK_GLOBAL_HANDLES)                     \

src/heap/mark-compact.h

@@ -22,7 +22,6 @@ namespace internal {
 // Forward declarations.
 class EvacuationJobTraits;
 class HeapObjectVisitor;
-class ItemParallelJob;
 class LocalWorkStealingMarkingDeque;
 class MarkCompactCollector;
 class MinorMarkCompactCollector;
@@ -277,9 +276,9 @@ class MarkCompactCollectorBase {
   // Returns whether this page should be moved according to heuristics.
   bool ShouldMovePage(Page* p, intptr_t live_bytes);
 
-  int CollectToSpaceUpdatingItems(ItemParallelJob* job);
   template <RememberedSetType type>
-  int CollectRememberedSetUpdatingItems(ItemParallelJob* job);
+  void UpdatePointersInParallel(base::Semaphore* semaphore);
+  void UpdateToSpacePointersInParallel(base::Semaphore* semaphore);
 
   int NumberOfParallelCompactionTasks(int pages);
   int NumberOfParallelPointerUpdateTasks(int pages, int slots);