Handle large rects better.

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 92 matching lines @@
 
   Vector2d OffsetFromOrigin() const { return Vector2d(x(), y()); }
 
   void SetRect(int x, int y, int width, int height) {
     origin_.SetPoint(x, y);
     // Ensure that width and height remain valid.
     set_width(width);
     set_height(height);
   }
 
+  // Use in place of SetRect() when you know the edges of the rectangle instead
+  // of the dimensions, rather than trying to determine the width/height
+  // yourself. This safely handles cases where the width/height would overflow.
+  void SetByBounds(int left, int top, int right, int bottom);
+
   // Shrink the rectangle by a horizontal and vertical distance on all sides.
   void Inset(int horizontal, int vertical) {
     Inset(horizontal, vertical, horizontal, vertical);
   }
 
   // Shrink the rectangle by the given insets.
   void Inset(const Insets& insets);
 
   // Shrink the rectangle by the specified amount on each side.
   void Inset(int left, int top, int right, int bottom);
@@ skipping 213 matching lines @@
 }
 
 // This is declared here for use in gtest-based unit tests but is defined in
 // the //ui/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_