[EXPERIMENT] MacViews: Implement Tab Dragging

ui/gfx/geometry/rect.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Defines a simple integer rectangle class.  The containment semantics
 // are array-like; that is, the coordinate (x, y) is considered to be
 // contained by the rectangle, but the coordinate (x + width, y) is not.
 // The class will happily let you create malformed rectangles (that is,
 // rectangles with negative width and/or height), but there will be assertions
 // in the operations (such as Contains()) to complain in this case.
@@ skipping 252 matching lines @@
       x : static_cast<int>(std::floor(rect.right() * x_scale));
   int b = rect.height() == 0 ?
       y : static_cast<int>(std::floor(rect.bottom() * y_scale));
   return Rect(x, y, r - x, b - y);
 }
 
 inline Rect ScaleToEnclosedRect(const Rect& rect, float scale) {
   return ScaleToEnclosedRect(rect, scale, scale);
 }
 
+// Will make the |p| fit inside |rect|, along the ledge that was closest to its
+// original position.
+GFX_EXPORT Point ConstrainToEnclosingRect(const Rect& rect, const Point& p);
+
 // This is declared here for use in gtest-based unit tests but is defined in
 // the gfx_test_support target. Depend on that to use this in your unit test.
 // This should not be used in production code - call ToString() instead.
 void PrintTo(const Rect& rect, ::std::ostream* os);
 
 }  // namespace gfx
 
 #endif  // UI_GFX_GEOMETRY_RECT_H_