More refactoring for Viewer

tools/viewer/GMSlide.cpp

 /*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
 /*
 * Copyright 2014 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
@@ skipping 12 matching lines @@
 void GMSlide::draw(SkCanvas* canvas) {
     // Do we care about timing the draw of the background (once)?
     // Does the GM ever rely on drawBackground to lazily compute something?
     fGM->drawBackground(canvas);
     fGM->drawContent(canvas);
 }
 
 bool GMSlide::animate(const SkAnimTimer& timer) {
     return fGM->animate(timer);
 }