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..65f5f6cef24171411d5cd8e35fad39a614d2aaa4 100755
--- a/src/gpu/glsl/GrGLSLCaps.h
+++ b/src/gpu/glsl/GrGLSLCaps.h
@@ -82,6 +82,14 @@ public:
         return fShaderDerivativeExtensionString;
     }
 
+    bool mustSwizzleInShader() const { return fMustSwizzleInShader; }
+
+    /**
+     * Returns a string which represents how to map from an internal GLFormat to a given
+     * GrPixelConfig. A draw side swizzle will then use this mapping to correctly set components.
+     */
+    const char* getSwizzleMap(GrPixelConfig config) const { return fConfigSwizzle[config]; }

[bsalomon, 2015/11/03 14:45:51]

Maybe change the last sentence to something like "mustSwizzleInShader()
determines whether this swizzle is applied in generated shader code or using
sampler state in the 3D API."?

[egdaniel, 2015/11/03 15:23:56]

Done.

+
     GrGLSLGeneration generation() const { return fGLSLGeneration; }
 
     /**
@@ -90,6 +98,8 @@ public:
     SkString dump() const override;
 
 private:
+    void onApplyOptionsOverrides(const GrContextOptions& options) override;
+
     GrGLSLGeneration fGLSLGeneration;
     
     bool fDropsTileOnZeroDivide : 1;
@@ -109,6 +119,9 @@ private:
 
     AdvBlendEqInteraction fAdvBlendEqInteraction;
 
+    bool        fMustSwizzleInShader;
+    const char* fConfigSwizzle[kGrPixelConfigCnt];
+
     friend class GrGLCaps;  // For initialization.
 
     typedef GrShaderCaps INHERITED;