Add missing overrides to clear and discard batch dumpInfo()

src/gpu/batches/GrClearBatch.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrClearBatch_DEFINED
 #define GrClearBatch_DEFINED
 
 #include "GrBatch.h"
 #include "GrBatchFlushState.h"
 #include "GrGpu.h"
 #include "GrRenderTarget.h"
 
 class GrClearBatch final : public GrBatch {
 public:
     GrClearBatch(const SkIRect& rect,  GrColor color, GrRenderTarget* rt)
         : fRect(rect)
         , fColor(color)
         , fRenderTarget(rt) {
         this->initClassID<GrClearBatch>();
         fBounds = SkRect::Make(rect);
     }
 
     const char* name() const override { return "Clear"; }
 
     uint32_t renderTargetUniqueID() const override { return fRenderTarget.get()->getUniqueID(); }
 
-    SkString dumpInfo() const {
+    SkString dumpInfo() const override {
         SkString string;
         string.printf("Color: 0x%08x, Rect [L: %d, T: %d, R: %d, B: %d], RT: 0x%p",
                       fColor, fRect.fLeft, fRect.fTop, fRect.fRight, fRect.fBottom,
                       fRenderTarget.get());
         return string;
     }
 
 private:
     bool onCombineIfPossible(GrBatch* t, const GrCaps& caps) override {
         // We could combine clears. TBD how much complexity to put here.
         return false;
     }
 
     void onPrepare(GrBatchFlushState*) override {}
 
     void onDraw(GrBatchFlushState* state) override {
         state->gpu()->clear(fRect, fColor, fRenderTarget.get());
     }
 
     SkIRect                                                 fRect;
     GrColor                                                 fColor;
     GrPendingIOResource<GrRenderTarget, kWrite_GrIOType>    fRenderTarget;
 };
 
 #endif