[views] Add metadata to View subclasses mainly in ash/shelf.

Folders include:
ash/shelf
ash/shortcut_viewer
ash/style

Low-Coverage-Reason: LARGE_SCALE_REFACTOR
Bug: 1485768
Change-Id: I55fdacb7e6b51f10200ca1050e50038ee27a5db2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5018059
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Commit-Queue: David Yeung <dayeung@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1225004}

diff --git a/ash/shelf/home_button.h b/ash/shelf/home_button.h
index 40942c5..ebcf700f 100644
--- a/ash/shelf/home_button.h
+++ b/ash/shelf/home_button.h

@@ -19,6 +19,7 @@
 #include "ash/shell_observer.h"
 #include "base/memory/raw_ptr.h"
 #include "base/scoped_observation.h"
+#include "ui/base/metadata/metadata_header_macros.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/transform.h"
 #include "ui/views/view_targeter_delegate.h"
@@ -55,6 +56,8 @@
                               public ShelfConfig::Observer,
                               public AppListModelProvider::Observer,
                               public QuickAppAccessModel::Observer {
+  METADATA_HEADER(HomeButton, ShelfControlButton)
+
  public:
   class ScopedNoClipRect {
    public:
@@ -86,8 +89,6 @@
     virtual void NudgeLabelShown(HomeButton* home_button) = 0;
   };
 
-  static const char kViewClassName[];
-
   explicit HomeButton(Shelf* shelf);
 
   HomeButton(const HomeButton&) = delete;