Make GrGLShaderBuilder check whether GrEffect advertised that it would require the dst color or frag

tests/GLProgramsTest.cpp

Index: tests/GLProgramsTest.cpp
diff --git a/tests/GLProgramsTest.cpp b/tests/GLProgramsTest.cpp
index 95187a6e39a2559005644e30353dcd7c4459ed48..d996cd74021e3c8b262f9aa9eec7fb40129cf5e8 100644
--- a/tests/GLProgramsTest.cpp
+++ b/tests/GLProgramsTest.cpp
@@ -63,7 +63,7 @@ void GrGLProgramDesc::setRandom(SkMWCRandom* random,
             const GrBackendEffectFactory& factory = (*stages[s]->getEffect())->getFactory();
             GrDrawEffect drawEffect(*stages[s], useLocalCoords);
             fEffectKeys[s] = factory.glEffectKey(drawEffect, gpu->glCaps());
-            if ((*stages[s]->getEffect())->willReadDst()) {
+            if ((*stages[s]->getEffect())->willReadDstColor()) {
                 dstRead = true;
             }
         }