Create swizzle table inside of glsl caps

src/gpu/glsl/GrGLSLCaps.h

Index: src/gpu/glsl/GrGLSLCaps.h
diff --git a/src/gpu/glsl/GrGLSLCaps.h b/src/gpu/glsl/GrGLSLCaps.h
index f93ef2766d18f376a0e65c1399ebf6151fbb4502..e703fb852384c7b4193b6fb66d6e5fa7ad9e2c8a 100755
--- a/src/gpu/glsl/GrGLSLCaps.h
+++ b/src/gpu/glsl/GrGLSLCaps.h
@@ -82,6 +82,15 @@ public:
         return fShaderDerivativeExtensionString;
     }
 
+    bool mustSwizzleInShader() const { return fMustSwizzleInShader; }
+
+    /**
+     * Returns a string which represents how to map from an internal GLFormat to a given
+     * GrPixelConfig. The function mustSwizzleInShader determines whether this swizzle is applied
+     * in the generated shader code or using sample state in the 3D API.
+     */
+    const char* getSwizzleMap(GrPixelConfig config) const { return fConfigSwizzle[config]; }
+
     GrGLSLGeneration generation() const { return fGLSLGeneration; }
 
     /**
@@ -90,6 +99,8 @@ public:
     SkString dump() const override;
 
 private:
+    void onApplyOptionsOverrides(const GrContextOptions& options) override;
+
     GrGLSLGeneration fGLSLGeneration;
     
     bool fDropsTileOnZeroDivide : 1;
@@ -109,6 +120,9 @@ private:
 
     AdvBlendEqInteraction fAdvBlendEqInteraction;
 
+    bool        fMustSwizzleInShader;
+    const char* fConfigSwizzle[kGrPixelConfigCnt];
+
     friend class GrGLCaps;  // For initialization.
 
     typedef GrShaderCaps INHERITED;