Remove Heap::IsPowerOf2().

Source/platform/heap/Heap.cpp

Index: Source/platform/heap/Heap.cpp
diff --git a/Source/platform/heap/Heap.cpp b/Source/platform/heap/Heap.cpp
index 04be9da29d692c6ca97b7d9c0da13a6c86ca9d54..2163e15d963b3259f0c6f7654ee177703cde54f8 100644
--- a/Source/platform/heap/Heap.cpp
+++ b/Source/platform/heap/Heap.cpp
@@ -77,13 +77,6 @@ static bool vTableInitialized(void* objectPointer)
     return !!(*reinterpret_cast<Address*>(objectPointer));
 }
 
-#if OS(WIN)
-static bool IsPowerOf2(size_t power)
-{
-    return !((power - 1) & power);
-}
-#endif
-
 static Address roundToBlinkPageBoundary(void* base)
 {
     return reinterpret_cast<Address>((reinterpret_cast<uintptr_t>(base) + blinkPageOffsetMask) & blinkPageBaseMask);