Refactor CRC2D::reset() to avoid non-additive SkCanvas state operations

third_party/WebKit/Source/modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.h"
 
 #include "bindings/modules/v8/OffscreenCanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContext.h"
 #include "core/frame/ImageBitmap.h"
 #include "core/frame/Settings.h"
 #include "core/workers/WorkerGlobalScope.h"
@@ skipping 188 matching lines @@
 }
 
 SkImageFilter* OffscreenCanvasRenderingContext2D::stateGetFilter() {
   // TODO: make getFilter accept nullptr
   // return state().getFilter(nullptr, nullptr, IntSize(width(), height()),
   // this);
   return nullptr;
 }
 
 void OffscreenCanvasRenderingContext2D::validateStateStack() const {
-#if ENABLE(ASSERT)
-  SkCanvas* skCanvas = existingDrawingCanvas();
-  if (skCanvas) {
-    ASSERT(static_cast<size_t>(skCanvas->getSaveCount()) ==
-           m_stateStack.size());
+#if DCHECK_IS_ON()
+  if (SkCanvas* skCanvas = existingDrawingCanvas()) {
+    DCHECK_EQ(static_cast<size_t>(skCanvas->getSaveCount()),
+              m_stateStack.size() + 1);
   }
 #endif
 }
 
 bool OffscreenCanvasRenderingContext2D::isContextLost() const {
   return false;
 }
 
 bool OffscreenCanvasRenderingContext2D::isPaintable() const {
   return this->imageBuffer();
 }
 }