Use intptr_t for onTouch argument.

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"
 #include "SkCanvas.h"
 #include "VulkanWindowContext.h"
 
 namespace sk_app {
 
 static bool default_char_func(SkUnichar c, uint32_t modifiers, void* userData) {
     return false;
 }
 
 static bool default_key_func(Window::Key key, Window::InputState state, uint32_t modifiers, 
                              void* userData) {
     return false;
 }
 
 static bool default_mouse_func(int x, int y, Window::InputState state, uint32_t modifiers, 
                                void* userData) {
     return false;
 }
 
-static bool default_touch_func(int owner, Window::InputState state, float x, float y,
+static bool default_touch_func(intptr_t owner, Window::InputState state, float x, float y,
                                void* userData) {
     return false;
 }
 
 static void default_ui_state_changed_func(
         const SkString& stateName, const SkString& stateValue, void* userData) {}
 
 static void default_paint_func(SkCanvas*, void* userData) {}
 
 Window::Window() : fCharFunc(default_char_func)
@@ skipping 14 matching lines @@
 }
 
 bool Window::onKey(Key key, InputState state, uint32_t modifiers) {
     return fKeyFunc(key, state, modifiers, fKeyUserData);
 }
 
 bool Window::onMouse(int x, int y, InputState state, uint32_t modifiers) {
     return fMouseFunc(x, y, state, modifiers, fMouseUserData);
 }
 
-bool Window::onTouch(int owner, InputState state, float x, float y) {
+bool Window::onTouch(intptr_t owner, InputState state, float x, float y) {
     return fTouchFunc(owner, state, x, y, fTouchUserData);
 }
 
 void Window::onUIStateChanged(const SkString& stateName, const SkString& stateValue) {
     return fUIStateChangedFunc(stateName, stateValue, fUIStateChangedUserData);
 }
 
 void Window::onPaint() {
     markInvalProcessed();
     sk_sp<SkSurface> backbuffer = fWindowContext->getBackbufferSurface();
@@ skipping 31 matching lines @@
         fIsContentInvalidated = true;
         onInval();
     }
 }
 
 void Window::markInvalProcessed() {
     fIsContentInvalidated = false;
 }
 
 }   // namespace sk_app