Make gfx::Rect class operations consistently mutate the class they are called on.

ui/app_list/apps_grid_view.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/app_list/apps_grid_view.h"
 
 #include <algorithm>
 
 #include "ui/app_list/app_list_item_model.h"
 #include "ui/app_list/app_list_item_view.h"
@@ skipping 384 matching lines @@
 
 void AppsGridView::CalculateIdealBounds() {
   gfx::Rect rect(GetContentsBounds());
   if (rect.IsEmpty())
     return;
 
   gfx::Size tile_size(kPreferredTileWidth, kPreferredTileHeight);
 
   gfx::Rect grid_rect(gfx::Size(tile_size.width() * cols_,
                                 tile_size.height() * rows_per_page_));
-  grid_rect = grid_rect.Intersect(rect);
+  grid_rect.Intersect(rect);
 
   // Page width including padding pixels. A tile.x + page_width means the same
   // tile slot in the next page.
   const int page_width = grid_rect.width() + kPagePadding;
 
   // If there is a transition, calculates offset for current and target page.
   const int current_page = pagination_model_->selected_page();
   const PaginationModel::Transition& transition =
       pagination_model_->transition();
   const bool is_valid =
@@ skipping 265 matching lines @@
 void AppsGridView::TransitionChanged() {
   // Update layout for valid page transition only since over-scroll no longer
   // animates app icons.
   const PaginationModel::Transition& transition =
       pagination_model_->transition();
   if (pagination_model_->is_valid_page(transition.target_page))
     Layout();
 }
 
 }  // namespace app_list