views: add Harmony dialog width support

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 c74f5461ab9f131376a6261deb563a448be75c49..05a1c18f45b7ec294778bc4058a2a5ccec9b9dd2 100644
--- a/ui/views/window/dialog_delegate.h
+++ b/ui/views/window/dialog_delegate.h
@@ -113,14 +113,30 @@ class VIEWS_EXPORT DialogDelegate : public ui::DialogModel,
   const DialogClientView* GetDialogClientView() const;
   DialogClientView* GetDialogClientView();
 
+  // Returns this dialog's width factor, if it has one. If it does not,
+  // returns zero.
+  int GetWidthFactor() const;

[Evan Stade, 2016/10/05 19:52:29]

I would expect this to either return an int that is the width in px (factor *
32) or an instance of DialogWidth

+
  protected:
   // Overridden from WidgetDelegate:
   ui::AXRole GetAccessibleWindowRole() const override;
 
+  // These values are in the 32px units the Harmony spec uses.

[Evan Stade, 2016/10/05 19:52:29]

a/units/increments

+  enum class DialogWidth {
+    UNSPECIFIED = 0,
+    SMALL = 10,
+    MEDIUM = 14,
+    LARGE = 16,
+  };
+
+  void set_dialog_width(DialogWidth width) { dialog_width_ = width; }
+
  private:
   // A flag indicating whether this dialog is able to use the custom frame
   // style for dialogs.
   bool supports_custom_frame_;
+
+  DialogWidth dialog_width_ = DialogWidth::UNSPECIFIED;
 };
 
 // A DialogDelegate implementation that is-a View. Used to override GetWidget()