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

Source/wtf/WTF.h

Index: Source/wtf/WTF.h
diff --git a/Source/wtf/WTF.h b/Source/wtf/WTF.h
index 27c8a2e8bea893859a4a694e7759cd17c23ba041..402b60416afbd4193abe1490ea944024ff858337 100644
--- a/Source/wtf/WTF.h
+++ b/Source/wtf/WTF.h
@@ -34,6 +34,7 @@
 #include "wtf/Compiler.h"
 #include "wtf/CurrentTime.h"
 #include "wtf/PartitionAlloc.h"
+#include <limits.h>
 
 namespace WTF {
 
@@ -52,6 +53,33 @@ private:
 };
 
 
+class QuantizedAllocation {

[abarth-chromium, 2013/09/07 05:08:24]

Why is this in WTF.h?  Please put it in its own header.

+public:
+    static const size_t kMaxAllocation = 32768;
+    static const size_t kMaxRounding = 4096;
+    static const size_t kMinRounding = 16;
+    static const size_t kMinRoundingLimit = 256;
+    static const size_t kTableSize = kMaxAllocation / kMinRoundingLimit;

[abarth-chromium, 2013/09/07 05:08:24]

Can you add some comments explaining where these numbers come from?

+
+    // Using "unsigned" is not a limitation because Chromium's max malloc() is 2GB even on 64-bit.
+    static const size_t kMaxUnquantizedAllocation = UINT_MAX - kMaxRounding;
+
+    static void init();
+
+    static size_t quantizedSize(size_t size)
+    {
+        size_t roundToLessOne;
+        if (UNLIKELY(size >= kMaxAllocation))
+            roundToLessOne = kMaxRounding - 1;
+        else
+            roundToLessOne = table[size / kMinRoundingLimit];
+        return (size + roundToLessOne) & ~roundToLessOne;
+    }
+
+private:
+    static unsigned short table[kTableSize];
+};
+
 } // namespace WTF
 
 #endif // WTF_h