[heap] pause observers during mark-compact

src/heap/spaces.h

Index: src/heap/spaces.h
diff --git a/src/heap/spaces.h b/src/heap/spaces.h
index 5e473426028dc6dc3d21b931013781471a051836..94ab4dc513e1bb296ccd7d5bb05daa8b661345b7 100644
--- a/src/heap/spaces.h
+++ b/src/heap/spaces.h
@@ -2755,9 +2755,6 @@ class NewSpace : public Space {
   // Removes a previously installed observer.
   void RemoveInlineAllocationObserver(InlineAllocationObserver* observer);
 
-  void PauseInlineAllocationObservers();
-  void ResumeInlineAllocationObservers();
-
   void DisableInlineAllocationSteps() {
     top_on_previous_step_ = 0;
     UpdateInlineAllocationLimit(0);
@@ -2879,10 +2876,28 @@ class NewSpace : public Space {
                             size_t size);
   intptr_t GetNextInlineAllocationStepSize();
   void StartNextInlineAllocationStep();
+  void PauseInlineAllocationObservers();
+  void ResumeInlineAllocationObservers();
 
+  friend class PauseInlineAllocationObserversScope;
   friend class SemiSpaceIterator;
 };
 
+class PauseInlineAllocationObserversScope {
+ public:
+  explicit PauseInlineAllocationObserversScope(NewSpace* new_space)
+      : new_space_(new_space) {
+    new_space_->PauseInlineAllocationObservers();
+  }
+  ~PauseInlineAllocationObserversScope() {
+    new_space_->ResumeInlineAllocationObservers();
+  }
+
+ private:
+  NewSpace* new_space_;
+  DISALLOW_COPY_AND_ASSIGN(PauseInlineAllocationObserversScope);
+};
+
 // -----------------------------------------------------------------------------
 // Compaction space that is used temporarily during compaction.