Simplify StackBounds.

Source/wtf/StackBounds.h

 /*
  * Copyright (C) 2010, 2013 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 34 matching lines @@
     {
         StackBounds bounds;
         bounds.initialize();
         bounds.checkConsistency();
         return bounds;
     }
 
     bool isSafeToRecurse(size_t minAvailableDelta = s_defaultAvailabilityDelta) const
     {
         checkConsistency();
-        if (isGrowingDownward())
-            return current() >= recursionLimit(minAvailableDelta);
-        return current() <= recursionLimit(minAvailableDelta);
+        return current() >= recursionLimit(minAvailableDelta);
     }
 
     void* origin() const
     {
         ASSERT(m_origin);
         return m_origin;
     }
 
     size_t size() const
     {
-        if (isGrowingDownward())
-            return static_cast<char*>(m_origin) - static_cast<char*>(m_bound);
-        return static_cast<char*>(m_bound) - static_cast<char*>(m_origin);
+        return static_cast<char*>(m_origin) - static_cast<char*>(m_bound);
     }
 
 private:
     StackBounds()
         : m_origin(0)
         , m_bound(0)
     {
     }
 
     void initialize();
 
     void* current() const
     {
         checkConsistency();
         void* currentPosition = &currentPosition;
         return currentPosition;
     }
 
     void* recursionLimit(size_t minAvailableDelta = s_defaultAvailabilityDelta) const
     {
         checkConsistency();
-        if (isGrowingDownward())
-            return static_cast<char*>(m_bound) + minAvailableDelta;
-        return static_cast<char*>(m_bound) - minAvailableDelta;
-    }
-
-    bool isGrowingDownward() const
-    {
-        ASSERT(m_origin && m_bound);
-        return true;
+        return static_cast<char*>(m_bound) + minAvailableDelta;
     }
 
     void checkConsistency() const
     {
 #if !ASSERT_DISABLED
         void* currentPosition = &currentPosition;
         ASSERT(m_origin != m_bound);
-        ASSERT(isGrowingDownward()
-            ? (currentPosition < m_origin && currentPosition > m_bound)
-            : (currentPosition > m_origin && currentPosition < m_bound));
+        ASSERT(currentPosition < m_origin && currentPosition > m_bound);
 #endif
     }
 
     void* m_origin;
     void* m_bound;
 
     friend class StackStats;
 };
 
 } // namespace WTF
 
 using WTF::StackBounds;
 
 #endif