Optimize damage region tracking under Android

* java/org/gnu/emacs/EmacsDrawLine.java (perform):

* java/org/gnu/emacs/EmacsDrawRectangle.java (perform): Call
damageRect with integer coordinates in lieu of consing a new
Rect.

* java/org/gnu/emacs/EmacsDrawable.java (damageRect) <IIII>:
Declare a new variant of damageRect, accepting four integers
designating the extents of the damage rectangle.

* java/org/gnu/emacs/EmacsPixmap.java (damageRect) <IIII>: New
stub.

* java/org/gnu/emacs/EmacsView.java (damageRect) <IIII>:
Implement this overloaded variant of damageRect.

* java/org/gnu/emacs/EmacsWindow.java (damageRect): Ditto.

* src/android.c (android_init_emacs_drawable)
(android_init_emacs_window): Move search for `damageRect' to
android_init_emacs_window.
(android_damage_window): Call IIII variant of `damageRect' to
avoid consing a new rectangle.  Ameliorate dynamic method
dispatch overhead.

java/org/gnu/emacs/EmacsView.java

@@ -437,6 +437,16 @@ public final class EmacsView extends ViewGroup
     damageRegion.union (damageRect);
   }
 
+  /* This function enables damage to be recorded without consing a new
+     Rect object.  */
+
+  public void
+  damageRect (int left, int top, int right, int bottom)
+  {
+    EmacsService.checkEmacsThread ();
+    damageRegion.op (left, top, right, bottom, Region.Op.UNION);
+  }
+
   /* This method is called from both the UI thread and the Emacs
      thread.  */