Adding metadata to MicView

This is part of the "Views Posse" effort. See this document:
https://docs.google.com/document/d/1Rst3792TjXtVA8k8GXaPD8MnuB1JAneSOpIILdA4268/edit?usp=sharing

Bug: 1159562
Test: build
Change-Id: I4a9cb578e0cc7af1eb78d1af4f7c9c7b92926ebb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2602959Reviewed-by: Allen Bauer <kylixrd@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Shengsong Tan <sstan@google.com>
Cr-Commit-Position: refs/heads/master@{#840890}

ash/assistant/ui/dialog_plate/mic_view.cc

@@ -13,6 +13,7 @@
 #include "ash/public/cpp/assistant/controller/assistant_ui_controller.h"
 #include "ui/views/layout/box_layout.h"
 #include "ui/views/layout/fill_layout.h"
+#include "ui/views/metadata/metadata_impl_macros.h"
 
 namespace ash {
 
@@ -41,10 +42,6 @@ MicView::~MicView() {
     AssistantInteractionController::Get()->GetModel()->RemoveObserver(this);
 }
 
-const char* MicView::GetClassName() const {
-  return "MicView";
-}
-
 gfx::Size MicView::CalculatePreferredSize() const {
   return gfx::Size(kPreferredSizeDip, GetHeightForWidth(kPreferredSizeDip));
 }
@@ -127,4 +124,7 @@ void MicView::UpdateState(bool animate) {
   logo_view_->SetState(mic_state, animate);
 }
 
+BEGIN_METADATA(MicView, AssistantButton)
+END_METADATA
+
 }  // namespace ash

ash/assistant/ui/dialog_plate/mic_view.h

@@ -12,6 +12,7 @@
 #include "base/component_export.h"
 #include "base/macros.h"
 #include "base/scoped_observer.h"
+#include "ui/views/metadata/metadata_header_macros.h"
 
 namespace ash {
 
@@ -24,12 +25,14 @@ class COMPONENT_EXPORT(ASSISTANT_UI) MicView
       public AssistantControllerObserver,
       public AssistantInteractionModelObserver {
  public:
+  METADATA_HEADER(MicView);
+
   MicView(AssistantButtonListener* listener,
           AssistantButtonId button_id);
+  MicView(const MicView&) = delete;
+  MicView& operator=(const MicView&) = delete;
   ~MicView() override;
 
-  // AssistantButton:
-  const char* GetClassName() const override;
   gfx::Size CalculatePreferredSize() const override;
   int GetHeightForWidth(int width) const override;
 
@@ -57,8 +60,6 @@ class COMPONENT_EXPORT(ASSISTANT_UI) MicView
 
   ScopedObserver<AssistantController, AssistantControllerObserver>
       assistant_controller_observer_{this};
-
-  DISALLOW_COPY_AND_ASSIGN(MicView);
 };
 
 }  // namespace ash