[EXPERIMENT] MacViews: Implement Tab Dragging

ui/gfx/geometry/rect.cc

Index: ui/gfx/geometry/rect.cc
diff --git a/ui/gfx/geometry/rect.cc b/ui/gfx/geometry/rect.cc
index e7a3aa2aac93f14eb96c4832a130f4bbeafa9253..a8e628792cce51a70c09ca0973b3f483eaaa6e2d 100644
--- a/ui/gfx/geometry/rect.cc
+++ b/ui/gfx/geometry/rect.cc
@@ -290,4 +290,17 @@ Rect BoundingRect(const Point& p1, const Point& p2) {
   return Rect(rx, ry, rr - rx, rb - ry);
 }
 
+Point ConstrainToEnclosingRect(const Rect& rect, const Point& p) {
+  Point result = p;
+  if (result.x() < rect.x())
+    result.set_x(rect.x());
+  if (result.y() < rect.y())
+    result.set_y(rect.y());
+  if (result.x() > rect.right())
+    result.set_x(rect.right());
+  if (result.y() > rect.bottom())
+    result.set_y(rect.bottom());
+  return result;
+}
+
 }  // namespace gfx