Change random number generator for tests to SkMWCRandom

tests/InfRectTest.cpp

Index: tests/InfRectTest.cpp
===================================================================
--- tests/InfRectTest.cpp	(revision 7902)
+++ tests/InfRectTest.cpp	(working copy)
@@ -35,7 +35,7 @@
                         gData[index].fRect.centerY() == gData[index].fCenter.y());
     }
 
-    SkRandom rand;
+    SkMWCRandom rand;
     for (int i = 0; i < 10000; ++i) {
         SkIRect r;