Remove confusing behavior of Rect::intersect() and rename

bug:24670525

Removes silly 'do nothing if rects do not intersect' behavior, and
changes the name to clarify the difference (contrasting against
SkRect::intersect())

bug:24670525

Change-Id: Id2ca1cfea1a9d720d4dc70b251f426d9916f8b53
diff --git a/libs/hwui/ClipArea.h b/libs/hwui/ClipArea.h
index 38fefe5..f88fd92 100644
--- a/libs/hwui/ClipArea.h
+++ b/libs/hwui/ClipArea.h
@@ -33,7 +33,7 @@
     TransformedRectangle(const Rect& bounds, const Matrix4& transform);
 
     bool canSimplyIntersectWith(const TransformedRectangle& other) const;
-    bool intersectWith(const TransformedRectangle& other);
+    void intersectWith(const TransformedRectangle& other);
 
     bool isEmpty() const;