Added registerChild; transforms, textures, glKey automatically handled.

BUG=skia:

Review URL: https://codereview.chromium.org/1266633003
diff --git a/src/effects/SkMorphologyImageFilter.cpp b/src/effects/SkMorphologyImageFilter.cpp
index 20f76c1..eca5f00 100644
--- a/src/effects/SkMorphologyImageFilter.cpp
+++ b/src/effects/SkMorphologyImageFilter.cpp
@@ -318,8 +318,6 @@
 
     const char* name() const override { return "Morphology"; }
 
-    void getGLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder*) const override;
-
     GrGLFragmentProcessor* createGLInstance() const override;
 
 protected:
@@ -329,6 +327,8 @@
     float fRange[2];
 
 private:
+    void onGetGLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder*) const override;
+
     bool onIsEqual(const GrFragmentProcessor&) const override;
 
     void onComputeInvariantOutput(GrInvariantOutput* inout) const override;
@@ -513,7 +513,7 @@
 GrMorphologyEffect::~GrMorphologyEffect() {
 }
 
-void GrMorphologyEffect::getGLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const {
+void GrMorphologyEffect::onGetGLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const {
     GrGLMorphologyEffect::GenKey(*this, caps, b);
 }