Adjust gfx::Rect's width and height to avoid integer overflow

ui/gfx/geometry/rect.cc

 // 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.
 
 #include "ui/gfx/geometry/rect.h"
 
 #include <algorithm>
 
 #if defined(OS_WIN)
 #include <windows.h>
@@ skipping 53 matching lines @@
 }
 
 void Rect::Inset(int left, int top, int right, int bottom) {
   origin_ += Vector2d(left, top);
   set_width(std::max(width() - left - right, static_cast<int>(0)));
   set_height(std::max(height() - top - bottom, static_cast<int>(0)));
 }
 
 void Rect::Offset(int horizontal, int vertical) {
   origin_ += Vector2d(horizontal, vertical);
+  // Ensure that width and height remain valid.
+  set_width(width());
+  set_height(height());
 }
 
 void Rect::operator+=(const Vector2d& offset) {
   origin_ += offset;
+  // Ensure that width and height remain valid.
+  set_width(width());
+  set_height(height());
 }
 
 void Rect::operator-=(const Vector2d& offset) {
   origin_ -= offset;
 }
 
 Insets Rect::InsetsFrom(const Rect& inner) const {
   return Insets(inner.y() - y(),
                 inner.x() - x(),
                 bottom() - inner.bottom(),
@@ skipping 196 matching lines @@
 
 Rect BoundingRect(const Point& p1, const Point& p2) {
   int rx = std::min(p1.x(), p2.x());
   int ry = std::min(p1.y(), p2.y());
   int rr = std::max(p1.x(), p2.x());
   int rb = std::max(p1.y(), p2.y());
   return Rect(rx, ry, rr - rx, rb - ry);
 }
 
 }  // namespace gfx