[heap] Cleanup and fix GC flags / add testing infra

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 6e6da98d31e2842f202bd0c74132b77323c065b1..13e18d4f298bb58acf86d815bf75be1ee9b59498 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -134,6 +134,7 @@ Heap::Heap()
       ring_buffer_end_(0),
       promotion_queue_(this),
       configured_(false),
+      current_gc_flags_(Heap::kNoGCFlags),
       external_string_table_(this),
       chunks_queued_for_free_(NULL),
       gc_callbacks_depth_(0),
@@ -798,9 +799,9 @@ void Heap::CollectAllGarbage(int flags, const char* gc_reason,
   // Since we are ignoring the return value, the exact choice of space does
   // not matter, so long as we do not specify NEW_SPACE, which would not
   // cause a full GC.
-  mark_compact_collector_.SetFlags(flags);
+  set_current_gc_flags(flags);
   CollectGarbage(OLD_SPACE, gc_reason, gc_callback_flags);
-  mark_compact_collector_.SetFlags(kNoGCFlags);
+  set_current_gc_flags(kNoGCFlags);
 }
 
 
@@ -822,8 +823,7 @@ void Heap::CollectAllAvailableGarbage(const char* gc_reason) {
     isolate()->optimizing_compile_dispatcher()->Flush();
   }
   isolate()->ClearSerializerData();
-  mark_compact_collector()->SetFlags(kMakeHeapIterableMask |
-                                     kReduceMemoryFootprintMask);
+  set_current_gc_flags(kMakeHeapIterableMask | kReduceMemoryFootprintMask);
   isolate_->compilation_cache()->Clear();
   const int kMaxNumberOfAttempts = 7;
   const int kMinNumberOfAttempts = 2;
@@ -834,7 +834,7 @@ void Heap::CollectAllAvailableGarbage(const char* gc_reason) {
       break;
     }
   }
-  mark_compact_collector()->SetFlags(kNoGCFlags);
+  set_current_gc_flags(kNoGCFlags);
   new_space_.Shrink();
   UncommitFromSpace();
 }
@@ -882,10 +882,8 @@ bool Heap::CollectGarbage(GarbageCollector collector, const char* gc_reason,
     }
   }
 
-  if (collector == MARK_COMPACTOR &&
-      !mark_compact_collector()->finalize_incremental_marking() &&
-      !mark_compact_collector()->abort_incremental_marking() &&
-      !incremental_marking()->IsStopped() &&
+  if (collector == MARK_COMPACTOR && !ShouldFinalizeIncrementalMarking() &&
+      !ShouldAbortIncrementalMarking() && !incremental_marking()->IsStopped() &&
       !incremental_marking()->should_hurry() && FLAG_incremental_marking) {
     // Make progress in incremental marking.
     const intptr_t kStepSizeWhenDelayedByScavenge = 1 * MB;
@@ -956,8 +954,7 @@ bool Heap::CollectGarbage(GarbageCollector collector, const char* gc_reason,
 
   // Start incremental marking for the next cycle. The heap snapshot
   // generator needs incremental marking to stay off after it aborted.
-  if (!mark_compact_collector()->abort_incremental_marking() &&
-      incremental_marking()->IsStopped() &&
+  if (!ShouldAbortIncrementalMarking() && incremental_marking()->IsStopped() &&
       incremental_marking()->ShouldActivateEvenWithoutIdleNotification()) {
     incremental_marking()->Start(kNoGCFlags, kNoGCCallbackFlags, "GC epilogue");
   }
@@ -5664,8 +5661,7 @@ void Heap::SetOldGenerationAllocationLimit(intptr_t old_gen_size,
     factor = Min(factor, kConservativeHeapGrowingFactor);
   }
 
-  if (FLAG_stress_compaction ||
-      mark_compact_collector()->reduce_memory_footprint_) {
+  if (FLAG_stress_compaction || ShouldReduceMemory()) {
     factor = kMinHeapGrowingFactor;
   }