Allow dialogs to use a custom View as their title.

ui/views/bubble/bubble_frame_view.h

Index: ui/views/bubble/bubble_frame_view.h
diff --git a/ui/views/bubble/bubble_frame_view.h b/ui/views/bubble/bubble_frame_view.h
index 4f4d94647a9d20d963fecd7794bb06b640751441..9cae8620c916609e8f97f5001af826f4a6e402cf 100644
--- a/ui/views/bubble/bubble_frame_view.h
+++ b/ui/views/bubble/bubble_frame_view.h
@@ -8,17 +8,14 @@
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
+#include "ui/gfx/font_list.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/views/controls/button/button.h"
+#include "ui/views/controls/label.h"
 #include "ui/views/window/non_client_view.h"
 
-namespace gfx {
-class FontList;
-}
-
 namespace views {
 
-class Label;
 class BubbleBorder;
 class ImageView;
 
@@ -33,6 +30,9 @@ class VIEWS_EXPORT BubbleFrameView : public NonClientFrameView,
                   const gfx::Insets& content_margins);
   ~BubbleFrameView() override;
 
+  static std::unique_ptr<Label> CreateDefaultTitleLabel(
+      const base::string16& title_text);
+
   // Creates a close button used in the corner of the dialog.
   static Button* CreateCloseButton(ButtonListener* listener);
 
@@ -48,9 +48,10 @@ class VIEWS_EXPORT BubbleFrameView : public NonClientFrameView,
   void UpdateWindowTitle() override;
   void SizeConstraintsChanged() override;
 
-  // Set the FontList to be used for the title of the bubble.
-  // Caller must arrange to update the layout to have the call take effect.
-  void SetTitleFontList(const gfx::FontList& font_list);
+  // Sets a custom view to be the dialog title instead of the |default_title_|
+  // label. The title view is owned by this BubbleFrameView. If there is an
+  // existing title view it will be deleted.
+  void SetTitleView(View* title_view);

[sky, 2017/06/22 14:48:48]

Please add test coverage of this. Maybe that setting it and forcing a layout
results in a valid parent, the view being visible and with some non-empty
bounds.

[Bret, 2017/06/22 22:18:30]

See the change in bubble_dialog_delegate_unittest.cc. Added an assert for the
title view's parent. The title view being visible is up to the delegate, so I
didn't assert that.

 
   // View:
   const char* GetClassName() const override;
@@ -101,6 +102,14 @@ class VIEWS_EXPORT BubbleFrameView : public NonClientFrameView,
   FRIEND_TEST_ALL_PREFIXES(BubbleDelegateTest, CloseReasons);
   FRIEND_TEST_ALL_PREFIXES(BubbleDialogDelegateTest, CloseMethods);
 
+  const View* title() const {
+    return delegate_title_ ? delegate_title_ : default_title_;
+  }
+  View* title() {
+    return const_cast<View*>(
+        static_cast<const BubbleFrameView*>(this)->title());

[sky, 2017/06/22 14:48:48]

static_cast -> const_cast

[Peter Kasting, 2017/06/22 17:49:34]

The Meyers pattern is to use static_cast here, which I kind of agree with --
static_cast is basically the "safest" cast.

+  }
+
   // Mirrors the bubble's arrow location on the |vertical| or horizontal axis,
   // if the generated window bounds don't fit in the monitor bounds.
   void MirrorArrowIfOffScreen(bool vertical,
@@ -126,7 +135,8 @@ class VIEWS_EXPORT BubbleFrameView : public NonClientFrameView,
 
   // The optional title icon, title, and (x) close button.
   views::ImageView* title_icon_;
-  Label* title_;
+  Label* default_title_;

[sky, 2017/06/22 14:48:48]

It's quite subtle why there are two titles. Please document what the two are for
and when they are used.

[Bret, 2017/06/22 22:18:30]

Done.

+  View* delegate_title_;

[sky, 2017/06/22 14:48:48]

Why did you go with 'delegate' as the prefix for this? The title doesn't come
from the delegate, so it's mildly confusing. Maybe client_title_?

[Bret, 2017/06/22 22:18:30]

It was more associated with the delegate in the earlier versions of the patch
with CreateTitleView. How about "custom_title_"?

   Button* close_;
 
   // A view to contain the footnote view, if it exists.