Revert of removing equality / compute invariant loops from GrGeometryProcessors

src/gpu/GrGeometryProcessor.cpp

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrGeometryProcessor.h"
+
+#include "GrInvariantOutput.h"
+
+void GrGeometryProcessor::getInvariantOutputColor(GrInitInvariantOutput* out) const {
+    if (fHasVertexColor) {
+        if (fOpaqueVertexColors) {
+            out->setUnknownOpaqueFourComponents();
+        } else {
+            out->setUnknownFourComponents();
+        }
+    } else {
+        out->setKnownFourComponents(fColor);
+    }
+    this->onGetInvariantOutputColor(out);
+}
+
+void GrGeometryProcessor::getInvariantOutputCoverage(GrInitInvariantOutput* out) const {
+    this->onGetInvariantOutputCoverage(out);
+}