Added registerChild; transforms, textures, glKey automatically handled.

BUG=skia:

Review URL: https://codereview.chromium.org/1266633003
diff --git a/src/effects/SkLightingImageFilter.cpp b/src/effects/SkLightingImageFilter.cpp
index 898b094..0b5e3e8 100644
--- a/src/effects/SkLightingImageFilter.cpp
+++ b/src/effects/SkLightingImageFilter.cpp
@@ -533,13 +533,13 @@
 
     const char* name() const override { return "DiffuseLighting"; }
 
-    void getGLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder*) const override;
-
     GrGLFragmentProcessor* createGLInstance() const override;
 
     SkScalar kd() const { return fKD; }
 
 private:
+    void onGetGLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder*) const override;
+
     bool onIsEqual(const GrFragmentProcessor&) const override;
 
     GrDiffuseLightingEffect(GrProcessorDataManager*,
@@ -577,14 +577,14 @@
 
     const char* name() const override { return "SpecularLighting"; }
 
-    void getGLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder*) const override;
-
     GrGLFragmentProcessor* createGLInstance() const override;
 
     SkScalar ks() const { return fKS; }
     SkScalar shininess() const { return fShininess; }
 
 private:
+    void onGetGLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder*) const override;
+
     bool onIsEqual(const GrFragmentProcessor&) const override;
 
     GrSpecularLightingEffect(GrProcessorDataManager*,
@@ -1612,7 +1612,7 @@
             this->kd() == s.kd();
 }
 
-void GrDiffuseLightingEffect::getGLProcessorKey(const GrGLSLCaps& caps,
+void GrDiffuseLightingEffect::onGetGLProcessorKey(const GrGLSLCaps& caps,
                                                 GrProcessorKeyBuilder* b) const {
     GrGLDiffuseLightingEffect::GenKey(*this, caps, b);
 }
@@ -1814,7 +1814,7 @@
            this->shininess() == s.shininess();
 }
 
-void GrSpecularLightingEffect::getGLProcessorKey(const GrGLSLCaps& caps,
+void GrSpecularLightingEffect::onGetGLProcessorKey(const GrGLSLCaps& caps,
                                                 GrProcessorKeyBuilder* b) const {
     GrGLSpecularLightingEffect::GenKey(*this, caps, b);
 }