Start to propagate constness of GrPipelineBuilder up the stack

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"
@@ skipping 2658 matching lines @@
 }
 
 void GrGLGpu::unbindTextureFromFBO(GrGLenum fboTarget) {
     GR_GL_CALL(this->glInterface(), FramebufferTexture2D(fboTarget,
                                                          GR_GL_COLOR_ATTACHMENT0,
                                                          GR_GL_TEXTURE_2D,
                                                          0,
                                                          0));
 }
 
-bool GrGLGpu::initCopySurfaceDstDesc(const GrSurface* src, GrSurfaceDesc* desc) {
+bool GrGLGpu::initCopySurfaceDstDesc(const GrSurface* src, GrSurfaceDesc* desc) const {
     // If the src is a texture, we can implement the blit as a draw assuming the config is
     // renderable.
     if (src->asTexture() && this->caps()->isConfigRenderable(src->config(), false)) {
         desc->fOrigin = kDefault_GrSurfaceOrigin;
         desc->fFlags = kRenderTarget_GrSurfaceFlag;
         desc->fConfig = src->config();
         return true;
     }
 
     // We look for opportunities to use CopyTexSubImage, or fbo blit. If neither are
@@ skipping 466 matching lines @@
             this->setVertexArrayID(gpu, 0);
         }
         int attrCount = gpu->glCaps().maxVertexAttributes();
         if (fDefaultVertexArrayAttribState.count() != attrCount) {
             fDefaultVertexArrayAttribState.resize(attrCount);
         }
         attribState = &fDefaultVertexArrayAttribState;
     }
     return attribState;
 }