Implement touch control

tools/viewer/sk_app/android/surface_glue_android.h

Index: tools/viewer/sk_app/android/surface_glue_android.h
diff --git a/tools/viewer/sk_app/android/surface_glue_android.h b/tools/viewer/sk_app/android/surface_glue_android.h
index 1ce06674b9eead2ac60d6f13a5f8517f0d4797fe..20919768a064268d195489af084b98b4c4c78399 100644
--- a/tools/viewer/sk_app/android/surface_glue_android.h
+++ b/tools/viewer/sk_app/android/surface_glue_android.h
@@ -24,13 +24,16 @@ enum MessageType {
     kSurfaceDestroyed,
     kDestroyApp,
     kContentInvalidated,
-    kKeyPressed
+    kKeyPressed,
+    kTouched
 };
 
 struct Message {
     MessageType fType = kUndefined;
     ANativeWindow* fNativeWindow = nullptr;
-    int keycode = 0;
+    int fKeycode = 0;
+    int fTouchOwner, fTouchState;
+    float fTouchX, fTouchY;
 
     Message() {}
     Message(MessageType t) : fType(t) {}