GridLayout: Guard against layout queries while adding a view.

ui/views/layout/grid_layout.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/views/layout/grid_layout.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/macros.h"
@@ skipping 802 matching lines @@
 
 int GridLayout::GetPreferredHeightForWidth(const View* host, int width) const {
   DCHECK(host_ == host);
   gfx::Size pref;
   SizeRowsAndColumns(false, width, 0, &pref);
   return pref.height();
 }
 
 void GridLayout::SizeRowsAndColumns(bool layout, int width, int height,
                                     gfx::Size* pref) const {
+  // Protect against clients asking for metrics during the addition of a View.
+  // The View is in the hierarchy, but it will not be accounted for in the
+  // layout calculations at this point, so the result will be incorrect.
+  DCHECK(!adding_view_) << "GridLayout queried while adding a view.";
+
   // Make sure the master columns have been calculated.
   CalculateMasterColumnsIfNecessary();
   pref->SetSize(0, 0);
   if (rows_.empty())
     return;
 
   // Calculate the preferred width of each of the columns. Some views'
   // preferred heights are derived from their width, as such we need to
   // calculate the size of the columns first.
   for (const auto& column_set : column_sets_) {
@@ skipping 188 matching lines @@
 
 ColumnSet* GridLayout::GetLastValidColumnSet() {
   for (int i = current_row_ - 1; i >= 0; --i) {
     if (rows_[i]->column_set())
       return rows_[i]->column_set();
   }
   return nullptr;
 }
 
 }  // namespace views