Remove use of GrEffectRef from draw state and below.

R=robertphillips@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/372773002
diff --git a/src/gpu/gl/GrGLShaderBuilder.cpp b/src/gpu/gl/GrGLShaderBuilder.cpp
index 7d2152f..4b7de02 100644
--- a/src/gpu/gl/GrGLShaderBuilder.cpp
+++ b/src/gpu/gl/GrGLShaderBuilder.cpp
@@ -337,7 +337,7 @@
 
 const char* GrGLShaderBuilder::dstColor() {
     if (fCodeStage.inStageCode()) {
-        const GrEffectRef& effect = *fCodeStage.effectStage()->getEffect();
+        const GrEffect* effect = fCodeStage.effectStage()->getEffect();
         if (!effect->willReadDstColor()) {
             SkDEBUGFAIL("GrGLEffect asked for dst color but its generating GrEffect "
                          "did not request access.");
@@ -487,7 +487,7 @@
 
 const char* GrGLShaderBuilder::fragmentPosition() {
     if (fCodeStage.inStageCode()) {
-        const GrEffectRef& effect = *fCodeStage.effectStage()->getEffect();
+        const GrEffect* effect = fCodeStage.effectStage()->getEffect();
         if (!effect->willReadFragmentPosition()) {
             SkDEBUGFAIL("GrGLEffect asked for frag position but its generating GrEffect "
                          "did not request access.");