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

third_party/WebKit/Source/platform/graphics/UnacceleratedImageBufferSurface.cpp

 /*
  * Copyright (c) 2013, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 34 matching lines @@
     sk_sp<SkColorSpace> colorSpace)
     : ImageBufferSurface(size, opacityMode, colorSpace) {
   SkAlphaType alphaType =
       (Opaque == opacityMode) ? kOpaque_SkAlphaType : kPremul_SkAlphaType;
   SkImageInfo info =
       SkImageInfo::MakeN32(size.width(), size.height(), alphaType, colorSpace);
   SkSurfaceProps disableLCDProps(0, kUnknown_SkPixelGeometry);
   m_surface =
       SkSurface::MakeRaster(info, Opaque == opacityMode ? 0 : &disableLCDProps);
 
+  // Always save an initial frame, to support resetting the top level matrix
+  // and clip.
+  if (m_surface)
+    m_surface->getCanvas()->save();
+
   if (initializationMode == InitializeImagePixels) {
     if (m_surface)
       clear();
   }
 }
 
 UnacceleratedImageBufferSurface::~UnacceleratedImageBufferSurface() {}
 
 SkCanvas* UnacceleratedImageBufferSurface::canvas() {
   return m_surface->getCanvas();
 }
 
 bool UnacceleratedImageBufferSurface::isValid() const {
   return m_surface;
 }
 
 sk_sp<SkImage> UnacceleratedImageBufferSurface::newImageSnapshot(
     AccelerationHint,
     SnapshotReason) {
   return m_surface->makeImageSnapshot();
 }
 
 }  // namespace blink