views: support dialog width snapping once and for all

ui/views/window/dialog_delegate.h

Index: ui/views/window/dialog_delegate.h
diff --git a/ui/views/window/dialog_delegate.h b/ui/views/window/dialog_delegate.h
index 6a11e65bab68208995be4982a5df06165411a9b7..9f19c73a7eb0d7de39469e8338d50f968e503c91 100644
--- a/ui/views/window/dialog_delegate.h
+++ b/ui/views/window/dialog_delegate.h
@@ -88,6 +88,10 @@ class VIEWS_EXPORT DialogDelegate : public ui::DialogModel,
   // the typical.
   virtual void UpdateButton(LabelButton* button, ui::DialogButton type);
 
+  // Returns true if this dialog should snap the frame width based on the
+  // LayoutProvider's snapping.
+  virtual bool ShouldSnapFrameWidth() const;

[Peter Kasting, 2017/04/19 19:26:13]

Do we have a specific dialog that we're going to set this false for?  If so,
let's add that in this CL so it's motivated.  If not, I wonder if we should just
omit this entirely for now and add it later if we need it.

[Elly Fong-Jones, 2017/04/20 19:54:00]

Done.

+
   // Overridden from ui::DialogModel:
   int GetDialogButtons() const override;
   int GetDefaultDialogButton() const override;