Add compressed texture capabilities for GPU devices

src/gpu/gl/GrGLCaps.h

Index: src/gpu/gl/GrGLCaps.h
diff --git a/src/gpu/gl/GrGLCaps.h b/src/gpu/gl/GrGLCaps.h
index ea0f41245d20bedea2d4a0fa76f95510a09a024e..c2d808e4a54bdb63ba5544cdc6a5f2f481f60b1a 100644
--- a/src/gpu/gl/GrGLCaps.h
+++ b/src/gpu/gl/GrGLCaps.h
@@ -313,6 +313,8 @@ private:
     // This must be called after initFSAASupport().
     void initConfigRenderableTable(const GrGLContextInfo&);
 
+    void initCompressedTextureSupport(const GrGLContextInfo &);
+
     // tracks configs that have been verified to pass the FBO completeness when
     // used as a color attachment
     VerifiedColorConfigs fVerifiedColorConfigs;