Get rid of fastMallocGoodSize() and replace it with something generic.

Source/wtf/FastMalloc.cpp

Index: Source/wtf/FastMalloc.cpp
diff --git a/Source/wtf/FastMalloc.cpp b/Source/wtf/FastMalloc.cpp
index db32b55ed40a9d6aaddf610638775ae3f1953917..7979c1849a1d183acbe947671cb330acd5c3e6e0 100644
--- a/Source/wtf/FastMalloc.cpp
+++ b/Source/wtf/FastMalloc.cpp
@@ -213,15 +213,6 @@ char* fastStrDup(const char* src)
 
 namespace WTF {
 
-size_t fastMallocGoodSize(size_t bytes)
-{
-#if OS(DARWIN)
-    return malloc_good_size(bytes);
-#else
-    return bytes;
-#endif
-}
-
 void* fastMalloc(size_t n)
 {
     ASSERT(!isForbidden());
@@ -2466,13 +2457,6 @@ static inline TCMalloc_PageHeap* getPageHeap()
 
 #define pageheap getPageHeap()
 
-size_t fastMallocGoodSize(size_t bytes)
-{
-    if (!phinited)
-        TCMalloc_ThreadCache::InitModule();
-    return AllocationSize(bytes);
-}
-
 #if USE_BACKGROUND_THREAD_TO_SCAVENGE_MEMORY
 
 #if HAVE(DISPATCH_H) || OS(WINDOWS)