Move VertexBuilder to a GrGLFullShaderBuilder subclass

src/gpu/gl/GrGLVertexEffect.h

+/*
+ * 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 GrGLVertexEffect_DEFINED
+#define GrGLVertexEffect_DEFINED
+
+#include "GrGLEffect.h"
+
+/**
+ * If a GL effect needs a GrGLFullShaderBuilder* object to emit vertex code, then it must inherit
+ * from this class. Since paths don't have vertices, this class is only meant to be used internally
+ * by skia, for special cases.
+ */
+class GrGLVertexEffect : public GrGLEffect {
+public:
+    GrGLVertexEffect(const GrBackendEffectFactory& factory)
+        : INHERITED(factory) { fIsVertexEffect = true; }
+
+    /**
+     * This is similar to emitCode() in the base class, except it takes a full shader builder.
+     * This allows the effect subclass to emit vertex code.
+     */
+    virtual void emitCode(GrGLFullShaderBuilder* builder,
+                          const GrDrawEffect& drawEffect,
+                          EffectKey key,
+                          const char* outputColor,
+                          const char* inputColor,
+                          const TransformedCoordsArray& coords,
+                          const TextureSamplerArray& samplers) = 0;
+
+    /**
+     * Provide a default override for base class's emitCode() function.
+     */
+    virtual void emitCode(GrGLShaderBuilder* builder,
+                          const GrDrawEffect& drawEffect,
+                          EffectKey key,
+                          const char* outputColor,
+                          const char* inputColor,
+                          const TransformedCoordsArray& coords,
+                          const TextureSamplerArray& samplers) SK_OVERRIDE {
+        GrCrash("GrGLVertexEffect requires GrGLFullShaderBuilder* overload for emitCode().");
+    }
+
+private:
+    typedef GrGLEffect INHERITED;
+};
+
+#endif