fix warings. add SkTAbs()



git-svn-id: http://skia.googlecode.com/svn/trunk@7075 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/core/SkTypes.h b/include/core/SkTypes.h
index a8d283d..113fd00 100644
--- a/include/core/SkTypes.h
+++ b/include/core/SkTypes.h
@@ -283,6 +283,13 @@
 #endif
 }
 
+template <typename T> inline T SkTAbs(T value) {
+    if (value < 0) {
+        value = -value;
+    }
+    return value;
+}
+
 static inline int32_t SkMax32(int32_t a, int32_t b) {
     if (a < b)
         a = b;