Refactor GrGLUniformManager::UniformHandle to initialize itself by default

src/effects/gradients/SkTwoPointConicalGradient.cpp

Index: src/effects/gradients/SkTwoPointConicalGradient.cpp
diff --git a/src/effects/gradients/SkTwoPointConicalGradient.cpp b/src/effects/gradients/SkTwoPointConicalGradient.cpp
index 37b49f0d475a22c9eecfb2027649e32e8b475587..797a16374e8f575fa343e6d18c6a7516bd11f6e5 100644
--- a/src/effects/gradients/SkTwoPointConicalGradient.cpp
+++ b/src/effects/gradients/SkTwoPointConicalGradient.cpp
@@ -336,7 +336,6 @@ void SkTwoPointConicalGradient::flatten(
 
 // For brevity
 typedef GrGLUniformManager::UniformHandle UniformHandle;
-static const UniformHandle kInvalidUniformHandle = GrGLUniformManager::kInvalidUniformHandle;
 
 class GrGLConical2Gradient : public GrGLGradientEffect {
 public:
@@ -475,8 +474,6 @@ GrEffectRef* GrConical2Gradient::TestCreate(SkMWCRandom* random,
 GrGLConical2Gradient::GrGLConical2Gradient(const GrBackendEffectFactory& factory,
                                            const GrDrawEffect& drawEffect)
     : INHERITED(factory)
-    , fVSParamUni(kInvalidUniformHandle)
-    , fFSParamUni(kInvalidUniformHandle)
     , fVSVaryingName(NULL)
     , fFSVaryingName(NULL)
     , fCachedCenter(SK_ScalarMax)