Add overflow indicator count on Windows.

chrome/chrome_browser.gypi

Index: chrome/chrome_browser.gypi
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 79c1b71ec9d60935a845e92a3e2f4a8d3c6d6900..fd389ad7c954f66affd45e1e85353fc33f6c8a75 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -3241,6 +3241,9 @@
         'browser/ui/panels/panel_mouse_watcher_observer.h',
         'browser/ui/panels/panel_mouse_watcher_timer.cc',
         'browser/ui/panels/panel_mouse_watcher_win.cc',
+        'browser/ui/panels/panel_overflow_indicator.h',
+        'browser/ui/panels/panel_overflow_indicator_view.cc',
+        'browser/ui/panels/panel_overflow_indicator_view.h',
         'browser/ui/panels/panel_overflow_strip.cc',
         'browser/ui/panels/panel_overflow_strip.h',
         'browser/ui/panels/panel_settings_menu_model.cc',
@@ -4530,6 +4533,8 @@
             'browser/ui/panels/panel_browser_frame_view.h',
             'browser/ui/panels/panel_browser_view.cc',
             'browser/ui/panels/panel_browser_view.h',
+            'browser/ui/panels/panel_overflow_indicator_view.cc',
+            'browser/ui/panels/panel_overflow_indicator_view.h',
             'browser/ui/tabs/dock_info.cc',
             'browser/ui/tabs/tab_resources.cc',
             'browser/ui/views/extensions/extension_view.cc',
@@ -5151,6 +5156,8 @@
                 ['exclude', '^browser/ui/panels/panel_browser_frame_view.h'],
                 ['exclude', '^browser/ui/panels/panel_browser_view.cc'],
                 ['exclude', '^browser/ui/panels/panel_browser_view.h'],
+                ['exclude', '^browser/ui/panels/panel_overflow_indicator_view.cc'],
+                ['exclude', '^browser/ui/panels/panel_overflow_indicator_view.h'],
               ],
               'sources!': [
                 'browser/ui/toolbar/bookmark_sub_menu_model.cc',