views: implement dialog width snapping

ui/views/window/dialog_delegate.cc

Index: ui/views/window/dialog_delegate.cc
diff --git a/ui/views/window/dialog_delegate.cc b/ui/views/window/dialog_delegate.cc
index 9122b1033bb867694c0a3ae7ed03c7cd9fc450ca..a789aee29c0357ff1deed5d3ee13ab622adbe48c 100644
--- a/ui/views/window/dialog_delegate.cc
+++ b/ui/views/window/dialog_delegate.cc
@@ -227,6 +227,10 @@ DialogClientView* DialogDelegate::GetDialogClientView() {
   return GetWidget()->client_view()->AsDialogClientView();
 }
 
+bool DialogDelegate::ShouldSnapFrameWidth() const {
+  return true;

[Peter Kasting, 2017/04/06 06:32:16]

Since this patch already makes bubbles-that-aren't-dialogs not snap, do we
actually need this method?

+}
+
 ui::AXRole DialogDelegate::GetAccessibleWindowRole() const {
   return ui::AX_ROLE_DIALOG;
 }