Revert "heap: Minor marking tweaks"

This reverts commit 77cd5d73.

Reason for revert: pinpoint shows only regressions.

Original change's description:
> heap: Minor marking tweaks
> 
> 1) Traces show that it can take a relatively long time before Oilpan
>    starts flushing v8 references (e.g. ~10 steps spent just on the
>    bailout worklist). This CL moves v8 references flushing before
>    processing of the bailout worklist.
> 2) Traces also show that a shorter duration for the first marking step
>    can suffice.
> 
> Bug: 986235
> Change-Id: If7bad026e91f1fdf1899035bda049834e7bffab5
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2339356
> Commit-Queue: Omer Katz <omerkatz@chromium.org>
> Commit-Queue: Anton Bikineev <bikineev@chromium.org>
> Auto-Submit: Omer Katz <omerkatz@chromium.org>
> Reviewed-by: Anton Bikineev <bikineev@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#795059}

TBR=bikineev@chromium.org,omerkatz@chromium.org

Change-Id: I36bbadafcfe91a4f725537975ec06b1a9ac10e0a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 986235
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2340040Reviewed-by: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#795163}

third_party/blink/renderer/platform/heap/heap.cc

@@ -388,15 +388,6 @@ bool ThreadHeap::AdvanceMarking(MarkingVisitor* visitor,
       // Start with mutator-thread-only worklists (not fully constructed).
       // If time runs out, concurrent markers can take care of the rest.
 
-      {
-        ThreadHeapStatsCollector::EnabledScope inner_scope(
-            stats_collector(),
-            ThreadHeapStatsCollector::kMarkFlushV8References);
-        finished = FlushV8References(deadline);
-        if (!finished)
-          break;
-      }
-
       {
         ThreadHeapStatsCollector::EnabledScope inner_scope(
             stats_collector(), ThreadHeapStatsCollector::kMarkBailOutObjects);
@@ -416,6 +407,15 @@ bool ThreadHeap::AdvanceMarking(MarkingVisitor* visitor,
           break;
       }
 
+      {
+        ThreadHeapStatsCollector::EnabledScope inner_scope(
+            stats_collector(),
+            ThreadHeapStatsCollector::kMarkFlushV8References);
+        finished = FlushV8References(deadline);
+        if (!finished)
+          break;
+      }
+
       {
         ThreadHeapStatsCollector::EnabledScope inner_scope(
             stats_collector(),

third_party/blink/renderer/platform/heap/marking_scheduling_oracle.h

@@ -19,7 +19,7 @@ class PLATFORM_EXPORT MarkingSchedulingOracle {
   // Duration of one incremental marking step. Should be short enough that it
   // doesn't cause jank even though it is scheduled as a normal task.
   static constexpr base::TimeDelta kDefaultIncrementalMarkingStepDuration =
-      base::TimeDelta::FromMillisecondsD(0.1);
+      base::TimeDelta::FromMillisecondsD(0.5);
 
   // Minimum number of bytes that should be marked during an incremental
   // marking step.