Remove unused methods from GraphicsContextState

Source/platform/graphics/GraphicsContextState.h

Index: Source/platform/graphics/GraphicsContextState.h
diff --git a/Source/platform/graphics/GraphicsContextState.h b/Source/platform/graphics/GraphicsContextState.h
index 64c950ee2eca41a13838544114687059c8e0bfa8..8ad9d613f16a62f848d889a2344fee38ba9b92c9 100644
--- a/Source/platform/graphics/GraphicsContextState.h
+++ b/Source/platform/graphics/GraphicsContextState.h
@@ -76,11 +76,9 @@ public:
 
     Gradient* strokeGradient() const { return m_strokeGradient.get(); }
     void setStrokeGradient(const PassRefPtr<Gradient>, float);
-    void clearStrokeGradient();
 
     Pattern* strokePattern() const { return m_strokePattern.get(); }
     void setStrokePattern(const PassRefPtr<Pattern>, float);
-    void clearStrokePattern();
 
     const StrokeData& strokeData() const { return m_strokeData; }
     void setStrokeStyle(StrokeStyle);
@@ -97,11 +95,9 @@ public:
 
     Gradient* fillGradient() const { return m_fillGradient.get(); }
     void setFillGradient(const PassRefPtr<Gradient>, float);
-    void clearFillGradient();
 
     Pattern* fillPattern() const { return m_fillPattern.get(); }
     void setFillPattern(const PassRefPtr<Pattern>, float);
-    void clearFillPattern();
 
     // Path fill rule
     WindRule fillRule() const { return m_fillRule; }