Better performance for -LayoutUnit

third_party/WebKit/Source/wtf/SaturatedArithmetic.h

Index: third_party/WebKit/Source/wtf/SaturatedArithmetic.h
diff --git a/third_party/WebKit/Source/wtf/SaturatedArithmetic.h b/third_party/WebKit/Source/wtf/SaturatedArithmetic.h
index a627b532ddc9e310b6210422ed4bd847cec7a7dd..eec1c9b3606eaaa5a2956aedcc2788c543e87437 100644
--- a/third_party/WebKit/Source/wtf/SaturatedArithmetic.h
+++ b/third_party/WebKit/Source/wtf/SaturatedArithmetic.h
@@ -73,6 +73,13 @@ ALWAYS_INLINE int32_t saturatedSubtraction(int32_t a, int32_t b)
     return result;
 }
 
+ALWAYS_INLINE int32_t saturatedNegative(int32_t a)
+{
+    if (UNLIKELY(a == std::numeric_limits<int>::min()))
+        return std::numeric_limits<int>::max();
+    return -a;
+}
+
 inline int getMaxSaturatedSetResultForTesting(int FractionalShift)
 {
     // For C version the set function maxes out to max int, this differs from