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/src/effects/gradients/SkGradientShaderPriv.h b/src/effects/gradients/SkGradientShaderPriv.h
index 451bd2d..f7a4189 100644
--- a/src/effects/gradients/SkGradientShaderPriv.h
+++ b/src/effects/gradients/SkGradientShaderPriv.h
@@ -282,7 +282,7 @@
         passed to the gradient factory rather than the array.
     */
     static const int kMaxRandomGradientColors = 4;
-    static int RandomGradientParams(SkMWCRandom* r,
+    static int RandomGradientParams(SkRandom* r,
                                     SkColor colors[kMaxRandomGradientColors],
                                     SkScalar** stops,
                                     SkShader::TileMode* tm);