[Reland] Oilpan: Enable HeapCompaction for incremental marking

Enables HeapCompaction for kIncrementalIdleGC and kIncrementalV8FollowupGC.

Bug: 864425

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Commit-Queue: Keishi Hattori <keishi@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#603477}
Change-Id: I506868b5ea224714491fb4dfd9403e5311550255
Reviewed-on: https://chromium-review.googlesource.com/c/1316954Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605608}

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

@@ -368,14 +368,10 @@ bool HeapCompact::ShouldCompact(ThreadHeap* heap,
     return force_compaction_gc_;
   }
 
-  // TODO(keishi): Should be enable after fixing the crashes.
-  if (marking_type == BlinkGC::kIncrementalMarking)
-    return false;
-
-  // TODO(harukamt): Add kIncrementalIdleGC and kIncrementalV8FollowupGC when we
-  // enable heap compaction for incremental marking.
   if (reason != BlinkGC::GCReason::kIdleGC &&
       reason != BlinkGC::GCReason::kPreciseGC &&
+      reason != BlinkGC::GCReason::kIncrementalIdleGC &&
+      reason != BlinkGC::GCReason::kIncrementalV8FollowupGC &&
       reason != BlinkGC::GCReason::kForcedGC)
     return false;