Make progress in incremental marking if scavenge is delaying mark-sweep.

test/cctest/test-heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 
 #include <stdlib.h>
 
 #include "v8.h"
 
 #include "execution.h"
 #include "factory.h"
 #include "macro-assembler.h"
 #include "global-handles.h"
@@ skipping 1503 matching lines @@
 
   Handle<JSFunction> f =
       v8::Utils::OpenHandle(
           *v8::Handle<v8::Function>::Cast(
               v8::Context::GetCurrent()->Global()->Get(v8_str("f"))));
 
   CHECK(f->IsOptimized());
 
   while (!Marking::IsBlack(Marking::MarkBitFrom(f->code())) &&
          !marking->IsStopped()) {
-    marking->Step(MB);
+    // Discard any pending GC requests otherwise we will get GC when we enter
+    // code below.
+    marking->Step(MB, IncrementalMarking::NO_GC_VIA_STACK_GUARD);
   }
 
   CHECK(marking->IsMarking());
 
-  // Discard any pending GC requests otherwise we will get GC when we enter
-  // code below.
-  if (ISOLATE->stack_guard()->IsGCRequest()) {
-    ISOLATE->stack_guard()->Continue(GC_REQUEST);
-  }
-
   {
     v8::HandleScope scope;
     v8::Handle<v8::Object> global = v8::Context::GetCurrent()->Global();
     v8::Handle<v8::Function> g =
         v8::Handle<v8::Function>::Cast(global->Get(v8_str("g")));
     g->Call(global, 0, NULL);
   }
 
   HEAP->incremental_marking()->set_should_hurry(true);
   HEAP->CollectGarbage(OLD_POINTER_SPACE);
@@ skipping 45 matching lines @@
   // clearing correctly records slots in prototype transition array.
   i::FLAG_always_compact = true;
   Handle<Map> map(baseObject->map());
   CHECK(!space->LastPage()->Contains(map->prototype_transitions()->address()));
   CHECK(space->LastPage()->Contains(prototype->address()));
   baseObject->SetPrototype(*prototype, false)->ToObjectChecked();
   CHECK(map->GetPrototypeTransition(*prototype)->IsMap());
   HEAP->CollectAllGarbage(Heap::kNoGCFlags);
   CHECK(map->GetPrototypeTransition(*prototype)->IsMap());
 }