[heap] move GetNextInlineAllocationStepSize to Space

Some preperatory refactoring to allow observation of inline allocations
from Old Space.

BUG=chromium:633920

Change-Id: Ia1232591860729fcd8942d816aa454171d3aec33
Reviewed-on: https://chromium-review.googlesource.com/617923Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Ali Ijaz Sheikh <ofrobots@google.com>
Cr-Commit-Position: refs/heads/master@{#47413}

src/heap/heap.h

@@ -2669,9 +2669,7 @@ class AllocationObserver {
   intptr_t bytes_to_next_step_;
 
  private:
-  friend class LargeObjectSpace;
-  friend class NewSpace;
-  friend class PagedSpace;
+  friend class Space;
   DISALLOW_COPY_AND_ASSIGN(AllocationObserver);
 };
 

src/heap/spaces.cc

@@ -1381,6 +1381,17 @@ void Space::AllocationStep(Address soon_object, int size) {
   }
 }
 
+intptr_t Space::GetNextInlineAllocationStepSize() {
+  intptr_t next_step = 0;
+  for (int i = 0; i < allocation_observers_->length(); ++i) {
+    AllocationObserver* o = (*allocation_observers_)[i];
+    next_step = next_step ? Min(next_step, o->bytes_to_next_step())
+                          : o->bytes_to_next_step();
+  }
+  DCHECK(allocation_observers_->length() == 0 || next_step != 0);
+  return next_step;
+}
+
 PagedSpace::PagedSpace(Heap* heap, AllocationSpace space,
                        Executability executable)
     : Space(heap, space, executable), anchor_(this), free_list_(this) {
@@ -2097,18 +2108,6 @@ void NewSpace::StartNextInlineAllocationStep() {
   }
 }
 
-
-intptr_t NewSpace::GetNextInlineAllocationStepSize() {
-  intptr_t next_step = 0;
-  for (int i = 0; i < allocation_observers_->length(); ++i) {
-    AllocationObserver* o = (*allocation_observers_)[i];
-    next_step = next_step ? Min(next_step, o->bytes_to_next_step())
-                          : o->bytes_to_next_step();
-  }
-  DCHECK(allocation_observers_->length() == 0 || next_step != 0);
-  return next_step;
-}
-
 void NewSpace::AddAllocationObserver(AllocationObserver* observer) {
   Space::AddAllocationObserver(observer);
   StartNextInlineAllocationStep();

src/heap/spaces.h

@@ -969,6 +969,8 @@ class Space : public Malloced {
 #endif
 
  protected:
+  intptr_t GetNextInlineAllocationStepSize();
+
   std::unique_ptr<List<AllocationObserver*>> allocation_observers_;
   bool allocation_observers_paused_;
 
@@ -2746,7 +2748,6 @@ class NewSpace : public Space {
   // different when we cross a page boundary or reset the space.
   void InlineAllocationStep(Address top, Address new_top, Address soon_object,
                             size_t size);
-  intptr_t GetNextInlineAllocationStepSize();
   void StartNextInlineAllocationStep();
 
   friend class SemiSpaceIterator;