remove unneeded SkShader::validContext

include/effects/SkTransparentShader.h

Index: include/effects/SkTransparentShader.h
diff --git a/include/effects/SkTransparentShader.h b/include/effects/SkTransparentShader.h
index 55513eb53208796f87490a100a5f6d42686bf067..d9a3e5d7a1975523e3b8ac317979d571f57d2486 100644
--- a/include/effects/SkTransparentShader.h
+++ b/include/effects/SkTransparentShader.h
@@ -14,8 +14,6 @@ class SK_API SkTransparentShader : public SkShader {
 public:
     SkTransparentShader() {}
 
-    virtual SkShader::Context* createContext(const ContextRec&, void* storage) const
-            SK_OVERRIDE;
     virtual size_t contextSize() const SK_OVERRIDE;
 
     class TransparentShaderContext : public SkShader::Context {
@@ -36,6 +34,9 @@ public:
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTransparentShader)
 
+protected:
+    virtual Context* onCreateContext(const ContextRec&, void* storage) const SK_OVERRIDE;
+
 private:
     SkTransparentShader(SkReadBuffer& buffer) : INHERITED(buffer) {}