Revert r12825 and r12796 from trunk.

src/mark-compact.cc

Index: src/mark-compact.cc
diff --git a/src/mark-compact.cc b/src/mark-compact.cc
index 641293399e6297d6824c2d07ee1d0ecf6cddd91b..24730c6c0a5db4a56d379772c0079989dbd0a729 100644
--- a/src/mark-compact.cc
+++ b/src/mark-compact.cc
@@ -926,47 +926,6 @@ void CodeFlusher::ProcessSharedFunctionInfoCandidates() {
 }
 
 
-void CodeFlusher::EvictCandidate(JSFunction* function) {
-  ASSERT(!function->next_function_link()->IsUndefined());
-  Object* undefined = isolate_->heap()->undefined_value();
-
-  JSFunction* candidate = jsfunction_candidates_head_;
-  JSFunction* next_candidate;
-  if (candidate == function) {
-    next_candidate = GetNextCandidate(function);
-    jsfunction_candidates_head_ = next_candidate;
-    ClearNextCandidate(function, undefined);
-  } else {
-    while (candidate != NULL) {
-      next_candidate = GetNextCandidate(candidate);
-
-      if (next_candidate == function) {
-        next_candidate = GetNextCandidate(function);
-        SetNextCandidate(candidate, next_candidate);
-        ClearNextCandidate(function, undefined);
-      }
-
-      candidate = next_candidate;
-    }
-  }
-}
-
-
-void CodeFlusher::IteratePointersToFromSpace(ObjectVisitor* v) {
-  Heap* heap = isolate_->heap();
-
-  JSFunction** slot = &jsfunction_candidates_head_;
-  JSFunction* candidate = jsfunction_candidates_head_;
-  while (candidate != NULL) {
-    if (heap->InFromSpace(candidate)) {
-      v->VisitPointer(reinterpret_cast<Object**>(slot));
-    }
-    candidate = GetNextCandidate(*slot);
-    slot = GetNextCandidateSlot(*slot);
-  }
-}
-
-
 MarkCompactCollector::~MarkCompactCollector() {
   if (code_flusher_ != NULL) {
     delete code_flusher_;
@@ -1471,8 +1430,21 @@ void MarkCompactCollector::PrepareThreadForCodeFlushing(Isolate* isolate,
 void MarkCompactCollector::PrepareForCodeFlushing() {
   ASSERT(heap() == Isolate::Current()->heap());
 
-  // If code flushing is disabled, there is no need to prepare for it.
-  if (!is_code_flushing_enabled()) return;
+  // TODO(1609) Currently incremental marker does not support code flushing.
+  if (!FLAG_flush_code || was_marked_incrementally_) {
+    EnableCodeFlushing(false);
+    return;
+  }
+
+#ifdef ENABLE_DEBUGGER_SUPPORT
+  if (heap()->isolate()->debug()->IsLoaded() ||
+      heap()->isolate()->debug()->has_break_points()) {
+    EnableCodeFlushing(false);
+    return;
+  }
+#endif
+
+  EnableCodeFlushing(true);
 
   // Ensure that empty descriptor array is marked. Method MarkDescriptorArray
   // relies on it being marked before any other descriptor array.
@@ -2033,6 +2005,9 @@ void MarkCompactCollector::AfterMarking() {
   // Flush code from collected candidates.
   if (is_code_flushing_enabled()) {
     code_flusher_->ProcessCandidates();
+    // TODO(1609) Currently incremental marker does not support code flushing,
+    // we need to disable it before incremental marking steps for next cycle.
+    EnableCodeFlushing(false);
   }
 
   if (!FLAG_watch_ic_patching) {