Allow dialogs to use a custom View as their title.

ui/views/bubble/bubble_dialog_delegate.cc

Index: ui/views/bubble/bubble_dialog_delegate.cc
diff --git a/ui/views/bubble/bubble_dialog_delegate.cc b/ui/views/bubble/bubble_dialog_delegate.cc
index b8be537b9912cb78562f726d0e441f52bab0c8e4..9a19c4197b96567c0aefc6a546549874378bffb1 100644
--- a/ui/views/bubble/bubble_dialog_delegate.cc
+++ b/ui/views/bubble/bubble_dialog_delegate.cc
@@ -106,9 +106,6 @@ ClientView* BubbleDialogDelegateView::CreateClientView(Widget* widget) {
 NonClientFrameView* BubbleDialogDelegateView::CreateNonClientFrameView(
     Widget* widget) {
   BubbleFrameView* frame = new BubbleFrameView(title_margins_, margins_);
-  // Note: In CreateBubble, the call to SizeToContents() will cause
-  // the relayout that this call requires.
-  frame->SetTitleFontList(GetTitleFontList());
   frame->SetFootnoteView(CreateFootnoteView());
 
   BubbleBorder::Arrow adjusted_arrow = arrow();
@@ -123,6 +120,10 @@ const char* BubbleDialogDelegateView::GetClassName() const {
   return kViewClassName;
 }
 
+void BubbleDialogDelegateView::AddedToWidget() {
+  SetupTitleView();
+}
+
 void BubbleDialogDelegateView::OnWidgetDestroying(Widget* widget) {
   if (anchor_widget() == widget)
     SetAnchorView(NULL);
@@ -234,11 +235,15 @@ gfx::Rect BubbleDialogDelegateView::GetBubbleBounds() {
       adjust_if_offscreen_ && !anchor_minimized);
 }
 
-const gfx::FontList& BubbleDialogDelegateView::GetTitleFontList() const {
-  ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
-  if (ui::MaterialDesignController::IsSecondaryUiMaterial())
-    return rb.GetFontListWithDelta(ui::kTitleFontSizeDelta);
-  return rb.GetFontList(ui::ResourceBundle::MediumFont);
+View* BubbleDialogDelegateView::CreateTitleView(
+    const base::string16& title_text) {
+  return nullptr;
+}
+
+void BubbleDialogDelegateView::SetupTitleView() {
+  View* title_view = CreateTitleView(GetWindowTitle());
+  if (title_view)
+    GetBubbleFrameView()->SetTitleView(title_view);
 }
 
 void BubbleDialogDelegateView::OnNativeThemeChanged(