Clean up aligned allocation code in preparation for SIMD alignments.

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index 8ecf7ae1328df4e495242eb777a128b1e7d6efc0..15dd6bdce611e17551e2aa59ce188492c438e437 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -716,13 +716,11 @@ class Heap {
   MUST_USE_RESULT AllocationResult
       CopyJSObject(JSObject* source, AllocationSite* site = NULL);
 
-  // This method assumes overallocation of one word. It will store a filler
-  // before the object if the given object is not double aligned, otherwise
-  // it will place the filler after the object.
-  MUST_USE_RESULT HeapObject* EnsureAligned(HeapObject* object, int size,
-                                            AllocationAlignment alignment);
+  static int GetMaximumMisalignment(AllocationAlignment alignment);
+  static int GetMisalignment(Address address, AllocationAlignment alignment);
 
-  MUST_USE_RESULT HeapObject* PrecedeWithFiller(HeapObject* object);
+  MUST_USE_RESULT HeapObject* PrecedeWithFiller(HeapObject* object,
+                                                int filler_size);
 
   // Clear the Instanceof cache (used when a prototype changes).
   inline void ClearInstanceofCache();