Allow GrGLEffects to produce variable length keys.

src/effects/gradients/SkSweepGradient.cpp

Index: src/effects/gradients/SkSweepGradient.cpp
diff --git a/src/effects/gradients/SkSweepGradient.cpp b/src/effects/gradients/SkSweepGradient.cpp
index bb9d628968f3575d8bb98be299062cbead9cec6b..66e755a1bcdf9a8c695b9f738f63e1dc4b64bbd7 100644
--- a/src/effects/gradients/SkSweepGradient.cpp
+++ b/src/effects/gradients/SkSweepGradient.cpp
@@ -186,14 +186,14 @@ public:
 
     virtual void emitCode(GrGLShaderBuilder*,
                           const GrDrawEffect&,
-                          EffectKey,
+                          const GrEffectKey&,
                           const char* outputColor,
                           const char* inputColor,
                           const TransformedCoordsArray&,
                           const TextureSamplerArray&) SK_OVERRIDE;
 
-    static EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
-        return GenBaseGradientKey(drawEffect);
+    static void GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&, GrEffectKeyBuilder* b) {
+        b->add32(GenBaseGradientKey(drawEffect));
     }
 
 private:
@@ -256,12 +256,13 @@ GrEffect* GrSweepGradient::TestCreate(SkRandom* random,
 
 void GrGLSweepGradient::emitCode(GrGLShaderBuilder* builder,
                                  const GrDrawEffect&,
-                                 EffectKey key,
+                                 const GrEffectKey& key,
                                  const char* outputColor,
                                  const char* inputColor,
                                  const TransformedCoordsArray& coords,
                                  const TextureSamplerArray& samplers) {
-    this->emitUniforms(builder, key);
+    uint32_t baseKey = key.get32(0);
+    this->emitUniforms(builder, baseKey);
     SkString coords2D = builder->ensureFSCoords2D(coords, 0);
     const GrGLContextInfo ctxInfo = builder->ctxInfo();
     SkString t;
@@ -275,8 +276,7 @@ void GrGLSweepGradient::emitCode(GrGLShaderBuilder* builder,
         t.printf("atan(- %s.y, -1.0 * %s.x) * 0.1591549430918 + 0.5",
                  coords2D.c_str(), coords2D.c_str());
     }
-    this->emitColor(builder, t.c_str(), key,
-                          outputColor, inputColor, samplers);
+    this->emitColor(builder, t.c_str(), baseKey, outputColor, inputColor, samplers);
 }
 
 /////////////////////////////////////////////////////////////////////