Implement support for KHR_blend_equation_advanced

src/gpu/gl/GrGLCaps.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef GrGLCaps_DEFINED
 #define GrGLCaps_DEFINED
@@ skipping 381 matching lines @@
 
     /**
      * Resets the caps such that nothing is supported.
      */
     void reset() override;
 
     /**
      * Initializes the GrGLSLCaps to the set of features supported in the current
      * OpenGL context accessible via ctxInfo.
      */
-    bool init(const GrGLContextInfo& ctxInfo, const GrGLInterface* glInterface);
+    bool init(const GrGLContextInfo&, const GrGLInterface*, const GrGLCaps&);
 
     /**
      * Some helper functions for encapsulating various extensions to read FB Buffer on openglES
      *
      * TODO(joshualitt) On desktop opengl 4.2+ we can achieve something similar to this effect
      */
     bool fbFetchSupport() const { return fFBFetchSupport; }
 
     bool fbFetchNeedsCustomOutput() const { return fFBFetchNeedsCustomOutput; }
 
     const char* fbFetchColorName() const { return fFBFetchColorName; }
 
     const char* fbFetchExtensionString() const { return fFBFetchExtensionString; }
 
     bool dropsTileOnZeroDivide() const { return fDropsTileOnZeroDivide; }
 
+    bool mustEnableAdvancedBlendEquations() const { return fMustEnableAdvancedBlendEquations; }
+
     /**
     * Returns a string containing the caps info.
     */
     SkString dump() const override;
 
 private:
     // Must be called after fGeometryShaderSupport is initialized.
     void initShaderPrecisionTable(const GrGLContextInfo&, const GrGLInterface*);
 
     bool fDropsTileOnZeroDivide : 1;
     bool fFBFetchSupport : 1;
     bool fFBFetchNeedsCustomOutput : 1;
+    bool fMustEnableAdvancedBlendEquations : 1;
 
     const char* fFBFetchColorName;
     const char* fFBFetchExtensionString;
 
     typedef GrShaderCaps INHERITED;
 };
 
 
 #endif