Add samples to Viewer.

tools/viewer/SKPSlide.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.
 */
 
 #include "SKPSlide.h"
 
 #include "SkCanvas.h"
@@ skipping 30 matching lines @@
         return nullptr;
     }
 
     auto pic = SkPicture::MakeFromStream(stream.get());
     if (!pic) {
         SkDebugf("Could not read %s as an SkPicture.\n", path);
     }
     return pic;
 }
 
-void SKPSlide::load() {
+void SKPSlide::load(SkScalar, SkScalar) {
     fPic = read_picture(fPath.c_str());
     fCullRect = fPic->cullRect().roundOut();
 }
 
 void SKPSlide::unload() {
     fPic.reset(nullptr);
 }