Update Panel titlebar text and icon layout when resized on Mac.

chrome/browser/ui/panels/panel_titlebar_view_cocoa.h

Index: chrome/browser/ui/panels/panel_titlebar_view_cocoa.h
diff --git a/chrome/browser/ui/panels/panel_titlebar_view_cocoa.h b/chrome/browser/ui/panels/panel_titlebar_view_cocoa.h
index 28441303096d67361db53cfb228262fc55d76e18..0cd2fce69baaab2577cf35efbf2a06125c496264 100644
--- a/chrome/browser/ui/panels/panel_titlebar_view_cocoa.h
+++ b/chrome/browser/ui/panels/panel_titlebar_view_cocoa.h
@@ -66,8 +66,8 @@ enum PanelDragState {
 - (void)updateCloseButtonLayout;
 - (void)updateIconAndTitleLayout;
 
-// We need to update our look when the Chrome theme changes or window focus
-// changes.
+// Various events that we'll need to redraw our titlebar for.
+- (void)didChangeFrame:(NSNotification*)notification;
 - (void)didChangeTheme:(NSNotification*)notification;
 - (void)didChangeMainWindow:(NSNotification*)notification;
 
@@ -93,6 +93,8 @@ enum PanelDragState {
 
 - (PanelWindowControllerCocoa*)controller;
 
+- (NSTextField*)title;
+
 // Simulates click on a close button. Used to test panel closing.
 - (void)simulateCloseButtonClick;