Use intptr_t for onTouch argument.

tools/viewer/sk_app/Window.h

 /*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
 
 #ifndef Window_DEFINED
 #define Window_DEFINED
 
@@ skipping 93 matching lines @@
     enum InputState {
         kDown_InputState,
         kUp_InputState,
         kMove_InputState   // only valid for mouse
     };
 
     // return value of 'true' means 'I have handled this event'
     typedef bool(*OnCharFunc)(SkUnichar c, uint32_t modifiers, void* userData);
     typedef bool(*OnKeyFunc)(Key key, InputState state, uint32_t modifiers, void* userData);
     typedef bool(*OnMouseFunc)(int x, int y, InputState state, uint32_t modifiers, void* userData);
-    typedef bool(*OnTouchFunc)(int owner, InputState state, float x, float y, void* userData);
+    typedef bool(*OnTouchFunc)(intptr_t owner, InputState state, float x, float y, void* userData);
     typedef void(*OnUIStateChangedFunc)(
             const SkString& stateName, const SkString& stateValue, void* userData);
     typedef void(*OnPaintFunc)(SkCanvas*, void* userData);
 
     void registerCharFunc(OnCharFunc func, void* userData) {
         fCharFunc = func;
         fCharUserData = userData;
     }
 
     void registerKeyFunc(OnKeyFunc func, void* userData) {
@@ skipping 17 matching lines @@
     }
 
     void registerUIStateChangedFunc(OnUIStateChangedFunc func, void* userData) {
         fUIStateChangedFunc = func;
         fUIStateChangedUserData = userData;
     }
 
     bool onChar(SkUnichar c, uint32_t modifiers);
     bool onKey(Key key, InputState state, uint32_t modifiers);
     bool onMouse(int x, int y, InputState state, uint32_t modifiers);
-    bool onTouch(int owner, InputState state, float x, float y);  // multi-owner = multi-touch
+    bool onTouch(intptr_t owner, InputState state, float x, float y);  // multi-owner = multi-touch
     void onUIStateChanged(const SkString& stateName, const SkString& stateValue);
     void onPaint();
     void onResize(uint32_t width, uint32_t height);
 
     uint32_t width() { return fWidth; }
     uint32_t height() { return fHeight;  }
 
     virtual const DisplayParams& getDisplayParams();
     void setDisplayParams(const DisplayParams& params);
 
@@ skipping 22 matching lines @@
     virtual void onInval() = 0;
 
     // Uncheck fIsContentInvalided to allow future inval/onInval.
     void markInvalProcessed();
 
     bool fIsContentInvalidated = false;  // use this to avoid duplicate invalidate events
 };
 
 }   // namespace sk_app
 #endif