Change old PRG to be SkLCGRandom; change new one to SkRandom

The goal here is to get people to start using the new random number
generator, while leaving the old one in place so we don't have to 
rebaseline GMs.

R=reed@google.com, bsalomon@google.com

Author: jvanverth@google.com

Review URL: https://chromiumcodereview.appspot.com/23576015

git-svn-id: http://skia.googlecode.com/svn/trunk@11169 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/bench/AAClipBench.cpp b/bench/AAClipBench.cpp
index ef5ba15..276a8ff 100644
--- a/bench/AAClipBench.cpp
+++ b/bench/AAClipBench.cpp
@@ -94,7 +94,7 @@
     SkString fName;
     bool     fDoAA;
     SkRect   fDrawRect;
-    SkMWCRandom fRandom;
+    SkRandom fRandom;
 
     static const int kNumDraws = SkBENCHLOOP(2);
     static const int kNestingDepth = 3;