There is an unused rowBytes parameter being passed along.

src/gpu/gl/GrGLGpu.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrGLGpu.h"
 #include "GrGLGLSL.h"
 #include "GrGLStencilAttachment.h"
@@ skipping 631 matching lines @@
     desc.fWidth = wrapDesc.fWidth;
     desc.fHeight = wrapDesc.fHeight;
     desc.fSampleCnt = SkTMin(wrapDesc.fSampleCnt, this->caps()->maxSampleCount());
     desc.fOrigin = resolve_origin(wrapDesc.fOrigin, true);
 
     return GrGLRenderTarget::CreateWrapped(this, desc, idDesc, wrapDesc.fStencilBits);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 bool GrGLGpu::onGetWritePixelsInfo(GrSurface* dstSurface, int width, int height,
-                                   size_t rowBytes, GrPixelConfig srcConfig,
+                                   GrPixelConfig srcConfig,
                                    DrawPreference* drawPreference,
                                    WritePixelTempDrawInfo* tempDrawInfo) {
     if (kIndex_8_GrPixelConfig == srcConfig || GrPixelConfigIsCompressed(dstSurface->config())) {
         return false;
     }
 
     // This subclass only allows writes to textures. If the dst is not a texture we have to draw
     // into it. We could use glDrawPixels on GLs that have it, but we don't today.
     if (!dstSurface->asTexture()) {
         ElevateDrawPreference(drawPreference, kRequireDraw_DrawPreference);
@@ skipping 3180 matching lines @@
         if (GR_GL_TEXTURE_EXTERNAL == glTexture->target() ||
             GR_GL_TEXTURE_RECTANGLE == glTexture->target()) {
             copyParams->fFilter = GrTextureParams::kNone_FilterMode;
             copyParams->fWidth = texture->width();
             copyParams->fHeight = texture->height();
             return true;
         }
     }
     return false;
 }