There is an unused rowBytes parameter being passed along.

src/gpu/GrTest.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrTest.h"
 
 #include "GrBatchAtlas.h"
@@ skipping 278 matching lines @@
 public:
     MockGpu(GrContext* context, const GrContextOptions& options) : INHERITED(context) {
         fCaps.reset(new MockCaps(options));
     }
     ~MockGpu() override {}
 
     bool onGetReadPixelsInfo(GrSurface* srcSurface, int readWidth, int readHeight, size_t rowBytes,
                              GrPixelConfig readConfig, DrawPreference*,
                              ReadPixelTempDrawInfo*) override { return false; }
 
-    bool onGetWritePixelsInfo(GrSurface* dstSurface, int width, int height, size_t rowBytes,
+    bool onGetWritePixelsInfo(GrSurface* dstSurface, int width, int height,
                               GrPixelConfig srcConfig, DrawPreference*,
                               WritePixelTempDrawInfo*) override { return false; }
 
     void buildProgramDesc(GrProgramDesc*, const GrPrimitiveProcessor&,
                           const GrPipeline&) const override {}
 
     void discard(GrRenderTarget*) override {}
 
     bool onCopySurface(GrSurface* dst,
                        GrSurface* src,
@@ skipping 96 matching lines @@
     SkASSERT(nullptr == fGpu);
     fGpu = new MockGpu(this, options);
     SkASSERT(fGpu);
     this->initCommon(options);
 
     // We delete these because we want to test the cache starting with zero resources. Also, none of
     // these objects are required for any of tests that use this context. TODO: make stop allocating
     // resources in the buffer pools.
     fDrawingManager->abandon();
 }