Force incremental marking when called from idle notification.

BUG=
R=ernstm@chromium.org, jochen@chromium.org

Review URL: https://codereview.chromium.org/426243002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22854 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap/heap.cc

@@ -4169,7 +4169,7 @@ void Heap::MakeHeapIterable() {
 
 void Heap::AdvanceIdleIncrementalMarking(intptr_t step_size) {
   incremental_marking()->Step(step_size,
-                              IncrementalMarking::NO_GC_VIA_STACK_GUARD);
+                              IncrementalMarking::NO_GC_VIA_STACK_GUARD, true);
 
   if (incremental_marking()->IsComplete()) {
     bool uncommit = false;

src/heap/incremental-marking.cc

@@ -821,8 +821,8 @@ void IncrementalMarking::OldSpaceStep(intptr_t allocated) {
 }
 
 
-void IncrementalMarking::Step(intptr_t allocated_bytes,
-                              CompletionAction action) {
+void IncrementalMarking::Step(intptr_t allocated_bytes, CompletionAction action,
+                              bool force_marking) {
   if (heap_->gc_state() != Heap::NOT_IN_GC || !FLAG_incremental_marking ||
       !FLAG_incremental_marking_steps ||
       (state_ != SWEEPING && state_ != MARKING)) {
@@ -831,7 +831,7 @@ void IncrementalMarking::Step(intptr_t allocated_bytes,
 
   allocated_ += allocated_bytes;
 
-  if (allocated_ < kAllocatedThreshold &&
+  if (!force_marking && allocated_ < kAllocatedThreshold &&
       write_barriers_invoked_since_last_step_ <
           kWriteBarriersInvokedThreshold) {
     return;

src/heap/incremental-marking.h

@@ -83,7 +83,8 @@ class IncrementalMarking {
 
   void OldSpaceStep(intptr_t allocated);
 
-  void Step(intptr_t allocated, CompletionAction action);
+  void Step(intptr_t allocated, CompletionAction action,
+            bool force_marking = false);
 
   inline void RestartIfNotMarking() {
     if (state_ == COMPLETE) {