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/SkLightingImageFilter.cpp b/src/effects/SkLightingImageFilter.cpp
index 999b8f8..ecf9913 100644
--- a/src/effects/SkLightingImageFilter.cpp
+++ b/src/effects/SkLightingImageFilter.cpp
@@ -1026,13 +1026,13 @@
 #if SK_SUPPORT_GPU
 
 namespace {
-SkPoint3 random_point3(SkMWCRandom* random) {
+SkPoint3 random_point3(SkRandom* random) {
     return SkPoint3(SkScalarToFloat(random->nextSScalar1()),
                     SkScalarToFloat(random->nextSScalar1()),
                     SkScalarToFloat(random->nextSScalar1()));
 }
 
-SkLight* create_random_light(SkMWCRandom* random) {
+SkLight* create_random_light(SkRandom* random) {
     int type = random->nextULessThan(3);
     switch (type) {
         case 0: {
@@ -1168,7 +1168,7 @@
 
 GR_DEFINE_EFFECT_TEST(GrDiffuseLightingEffect);
 
-GrEffectRef* GrDiffuseLightingEffect::TestCreate(SkMWCRandom* random,
+GrEffectRef* GrDiffuseLightingEffect::TestCreate(SkRandom* random,
                                                  GrContext* context,
                                                  const GrDrawTargetCaps&,
                                                  GrTexture* textures[]) {
@@ -1386,7 +1386,7 @@
 
 GR_DEFINE_EFFECT_TEST(GrSpecularLightingEffect);
 
-GrEffectRef* GrSpecularLightingEffect::TestCreate(SkMWCRandom* random,
+GrEffectRef* GrSpecularLightingEffect::TestCreate(SkRandom* random,
                                                   GrContext* context,
                                                   const GrDrawTargetCaps&,
                                                   GrTexture* textures[]) {