Remove SkShader virtual method validContext

patch from issue 267923005

BUG=skia:
R=scroggo@google.com

Author: reed@google.com

Review URL: https://codereview.chromium.org/261773005

git-svn-id: http://skia.googlecode.com/svn/trunk@14573 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/core/SkComposeShader.h b/include/core/SkComposeShader.h
index ac3c32b..cfb03b9 100644
--- a/include/core/SkComposeShader.h
+++ b/include/core/SkComposeShader.h
@@ -34,8 +34,6 @@
     SkComposeShader(SkShader* sA, SkShader* sB, SkXfermode* mode = NULL);
     virtual ~SkComposeShader();
 
-    virtual bool validContext(const ContextRec&, SkMatrix* totalInverse = NULL) const SK_OVERRIDE;
-    virtual SkShader::Context* createContext(const ContextRec&, void*) const SK_OVERRIDE;
     virtual size_t contextSize() const SK_OVERRIDE;
 
     class ComposeShaderContext : public SkShader::Context {
@@ -70,6 +68,7 @@
 protected:
     SkComposeShader(SkReadBuffer& );
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
+    virtual Context* onCreateContext(const ContextRec&, void*) const SK_OVERRIDE;
 
 private:
     SkShader*   fShaderA;