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

ash/wm/base_layout_manager.cc

Index: ash/wm/base_layout_manager.cc
diff --git a/ash/wm/base_layout_manager.cc b/ash/wm/base_layout_manager.cc
index 1bf6434a25bc2630241e83748ecabc269df41e42..78019cdb64c400b6118097aca6f284125c8f8417 100644
--- a/ash/wm/base_layout_manager.cc
+++ b/ash/wm/base_layout_manager.cc
@@ -224,7 +224,9 @@ void BaseLayoutManager::AdjustWindowSizesForScreenChange() {
       gfx::Rect display_rect =
           ScreenAsh::GetDisplayWorkAreaBoundsInParent(window);
       // Put as much of the window as possible within the display area.
-      window->SetBounds(window->bounds().AdjustToFit(display_rect));
+      gfx::Rect bounds = window->bounds();
+      bounds.AdjustToFit(display_rect);
+      window->SetBounds(bounds);
     }
   }
 }