Add sRGB mode toggle to Viewer.

tools/viewer/sk_app/Window.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 "Window.h"
 
 #include "SkSurface.h"
@@ skipping 57 matching lines @@
     }
 
 }
 
 void Window::onResize(uint32_t w, uint32_t h) {
     fWidth = w;
     fHeight = h;
     fWindowContext->resize(w, h);
 }
 
+const DisplayParams& Window::getDisplayParams() {
+    return fWindowContext->getDisplayParams();
+}
+
+void Window::setDisplayParams(const DisplayParams& params) {
+    fWindowContext->setDisplayParams(params);
+}
+
 }   // namespace sk_app