Add flexible keybinding/command system to sk_app

tools/viewer/sk_app/win/Window_win.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_win.h"
 
 #include <tchar.h>
@@ skipping 75 matching lines @@
     SetWindowLongPtr(fHWnd, GWLP_USERDATA, (LONG_PTR)this);
 
     return true;
 }
 
 static Window::Key get_key(WPARAM vk) {
     static const struct {
         WPARAM      fVK;
         Window::Key fKey;
     } gPair[] = {
-        { VK_BACK, Window::kBack_Key },
-        { VK_CLEAR, Window::kBack_Key },
-        { VK_RETURN, Window::kOK_Key },
-        { VK_UP, Window::kUp_Key },
-        { VK_DOWN, Window::kDown_Key },
-        { VK_LEFT, Window::kLeft_Key },
-        { VK_RIGHT, Window::kRight_Key }
+        { VK_BACK, Window::Key::kBack },
+        { VK_CLEAR, Window::Key::kBack },
+        { VK_RETURN, Window::Key::kOK },
+        { VK_UP, Window::Key::kUp },
+        { VK_DOWN, Window::Key::kDown },
+        { VK_LEFT, Window::Key::kLeft },
+        { VK_RIGHT, Window::Key::kRight }
     };
     for (size_t i = 0; i < SK_ARRAY_COUNT(gPair); i++) {
         if (gPair[i].fVK == vk) {
             return gPair[i].fKey;
         }
     }
-    return Window::kNONE_Key;
+    return Window::Key::kNONE;
 }
 
 static uint32_t get_modifiers(UINT message, WPARAM wParam, LPARAM lParam) {
     uint32_t modifiers = 0;
 
     switch (message) {
         case WM_UNICHAR:
         case WM_CHAR:
             if (0 == (lParam & (1 << 30))) {
                 modifiers |= Window::kFirstPress_ModifierKey;
@@ skipping 156 matching lines @@
     fWindowContext = VulkanWindowContext::Create((void*)&platformData, params);
 
     return (SkToBool(fWindowContext));
 }
 
 void Window_win::inval() {
     InvalidateRect(fHWnd, nullptr, false);
 }
 
 }   // namespace sk_app