Let CLAHE_OCL reuse cv::CLAHE abstract class.

modules/ocl/include/opencv2/ocl/ocl.hpp

@@ -516,20 +516,8 @@ namespace cv
         CV_EXPORTS void equalizeHist(const oclMat &mat_src, oclMat &mat_dst);
         
         //! only 8UC1 is supported now
-        class CV_EXPORTS CLAHE
+        class CV_EXPORTS CLAHE : public cv::CLAHE
         {
-        public:
-            virtual void apply(const oclMat &src, oclMat &dst) = 0;
-
-            virtual void setClipLimit(double clipLimit) = 0;
-            virtual double getClipLimit() const = 0;
-
-            virtual void setTilesGridSize(Size tileGridSize) = 0;
-            virtual Size getTilesGridSize() const = 0;
-
-            virtual void collectGarbage() = 0;
-
-            virtual ~CLAHE() {}
         };
         CV_EXPORTS Ptr<cv::ocl::CLAHE> createCLAHE(double clipLimit = 40.0, Size tileGridSize = Size(8, 8));