Rename StageKey and related stuff.

R=robertphillips@google.com
Review URL: https://codereview.appspot.com/6785049

git-svn-id: http://skia.googlecode.com/svn/trunk@6130 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/effects/GrSingleTextureEffect.cpp b/src/gpu/effects/GrSingleTextureEffect.cpp
index 0ba748c..844bff7 100644
--- a/src/gpu/effects/GrSingleTextureEffect.cpp
+++ b/src/gpu/effects/GrSingleTextureEffect.cpp
@@ -29,7 +29,7 @@
         builder->fFSCode.append(";\n");
     }
 
-    static inline StageKey GenKey(const GrEffect&, const GrGLCaps&) { return 0; }
+    static inline EffectKey GenKey(const GrEffect&, const GrGLCaps&) { return 0; }
 
 private: