Revert of added support for PLS path rendering

src/gpu/batches/GrPLSPathRenderer.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 GrPLSPathRenderer_DEFINED
-#define GrPLSPathRenderer_DEFINED
-
-#include "GrPathRenderer.h"
-
-/*
- * Renders arbitrary antialiased paths using pixel local storage as a scratch buffer. The overall
- * technique is very similar to the approach presented in "Resolution independent rendering of 
- * deformable vector objects using graphics hardware" by Kokojima et al.
-
- * We first render the straight-line portions of the path (essentially pretending as if all segments
- * were kLine_Verb) as a triangle fan, using a fragment shader which updates the winding counts 
- * appropriately. We then render the curved portions of the path using a Loop-Blinn shader which 
- * calculates which portion of the triangle is covered by the quad (conics and cubics are split down
- * to quads). Where we diverge from Kokojima is that, instead of rendering into the stencil buffer 
- * and using built-in MSAA to handle straight-line antialiasing, we use the pixel local storage area
- * and calculate the MSAA ourselves in the fragment shader. Essentially, we manually evaluate the 
- * coverage of each pixel four times, storing four winding counts into the pixel local storage area,
- * and compute the final coverage based on those winding counts.
- *
- * Our approach is complicated by the need to perform antialiasing on straight edges as well, 
- * without relying on hardware MSAA. We instead bloat the triangles to ensure complete coverage, 
- * pass the original (un-bloated) vertices in to the fragment shader, and then have the fragment 
- * shader use these vertices to evaluate whether a given sample is located within the triangle or 
- * not. This gives us MSAA4 edges on triangles which line up nicely with no seams. We similarly face
- * problems on the back (flat) edges of quads, where we have to ensure that the back edge is 
- * antialiased in the same way. Similar to the triangle case, we pass in the two (unbloated) 
- * vertices defining the back edge of the quad and the fragment shader uses these vertex coordinates
- * to discard samples falling on the other side of the quad's back edge.
- */
-class GrPLSPathRenderer : public GrPathRenderer {
-public:
-    GrPLSPathRenderer();
-
-    bool onCanDrawPath(const CanDrawPathArgs& args) const override;
-
-protected:
-    bool onDrawPath(const DrawPathArgs& args) override;
-};
-
-#endif