Mark when effects and programs have vertex code

src/gpu/effects/GrVertexEffect.h

Index: src/gpu/effects/GrVertexEffect.h
diff --git a/src/gpu/effects/GrVertexEffect.h b/src/gpu/effects/GrVertexEffect.h
new file mode 100644
index 0000000000000000000000000000000000000000..387ec7aee913830ba01b2eb3226e2ae485ec0157
--- /dev/null
+++ b/src/gpu/effects/GrVertexEffect.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrVertexEffect_DEFINED
+#define GrVertexEffect_DEFINED
+
+#include "GrEffect.h"
+
+/**
+ * If an effect needs specialized vertex shader code, then it must inherit from this class.
+ * Otherwise it won't be able to add vertex attribs, and it might be given a vertexless shader
+ * program in emitCode.
+ */
+class GrVertexEffect : public GrEffect {
+public:
+    GrVertexEffect() { fHasVertexCode = true; }
+
+protected:
+    /**
+     * Subclasses call this from their constructor to register vertex attributes (at most
+     * kMaxVertexAttribs). This must only be called from the constructor because GrEffects are
+     * immutable.
+     */
+    void addVertexAttrib(GrSLType type) {
+        SkASSERT(fVertexAttribTypes.count() < kMaxVertexAttribs);
+        fVertexAttribTypes.push_back(type);
+    }
+
+private:
+    typedef GrEffect INHERITED;
+};
+
+#endif