Added IsViewClass<T> function for use in place of GetClassName() comparisons.

Added metadata to Tab, TabSlotView

https://docs.google.com/document/d/1FXacwqJjW4ircJ19gsypRnLAWMYmM8sFTyDCpBH48jI/edit?usp=sharing

Bug: 938501
Change-Id: I659ca7eea66d8b50e0609d08b29cfc8efd3b8809
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2429515
Commit-Queue: Allen Bauer <kylixrd@chromium.org>
Reviewed-by: Peter Boström <pbos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#810503}

chrome/browser/ui/views/global_media_controls/media_dialog_view_interactive_browsertest.cc

@@ -29,6 +29,7 @@
 #include "media/base/media_switches.h"
 #include "services/media_session/public/mojom/media_session.mojom.h"
 #include "ui/views/controls/button/image_button.h"
+#include "ui/views/view_utils.h"
 
 using media_session::mojom::MediaSessionAction;
 
@@ -527,7 +528,7 @@ class MediaDialogViewBrowserTest : public InProcessBrowserTest {
   // media_message_center::MediaNotificationViewImpl sets the tags of its action
   // buttons to the MediaSessionAction value.
   views::ImageButton* GetButtonForAction(views::View* view, int action) {
-    if (view->GetClassName() == views::ImageButton::kViewClassName) {
+    if (views::IsViewClass<views::ImageButton>(view)) {
       views::ImageButton* image_button = static_cast<views::ImageButton*>(view);
       if (image_button->tag() == action)
         return image_button;

chrome/browser/ui/views/tabs/tab.cc

@@ -76,6 +76,7 @@
 #include "ui/views/controls/button/image_button.h"
 #include "ui/views/controls/highlight_path_generator.h"
 #include "ui/views/controls/label.h"
+#include "ui/views/metadata/metadata_impl_macros.h"
 #include "ui/views/rect_based_targeting_utils.h"
 #include "ui/views/view.h"
 #include "ui/views/view_class_properties.h"
@@ -175,9 +176,6 @@ class Tab::TabCloseButtonObserver : public views::ViewObserver {
 
 // Tab -------------------------------------------------------------------------
 
-// static
-const char Tab::kViewClassName[] = "Tab";
-
 // static
 void Tab::SetShowHoverCardOnMouseHoverForTesting(bool value) {
   g_show_hover_card_on_mouse_hover = value;
@@ -423,10 +421,6 @@ void Tab::Layout() {
     focus_ring_->Layout();
 }
 
-const char* Tab::GetClassName() const {
-  return kViewClassName;
-}
-
 bool Tab::OnKeyPressed(const ui::KeyEvent& event) {
   if (event.key_code() == ui::VKEY_RETURN && !IsSelected()) {
     controller_->SelectTab(this, event);
@@ -1049,3 +1043,6 @@ void Tab::UpdateForegroundColors() {
 
   SchedulePaint();
 }
+
+BEGIN_METADATA(Tab, TabSlotView)
+END_METADATA

chrome/browser/ui/views/tabs/tab.h

@@ -24,6 +24,7 @@
 #include "ui/views/controls/button/button.h"
 #include "ui/views/controls/focus_ring.h"
 #include "ui/views/masked_targeter_delegate.h"
+#include "ui/views/metadata/metadata_header_macros.h"
 #include "ui/views/view_observer.h"
 
 class AlertIndicator;
@@ -53,8 +54,7 @@ class Tab : public gfx::AnimationDelegate,
             public views::ViewObserver,
             public TabSlotView {
  public:
-  // The Tab's class name.
-  static const char kViewClassName[];
+  METADATA_HEADER(Tab);
 
   // When the content's width of the tab shrinks to below this size we should
   // hide the close button on inactive tabs. Any smaller and they're too easy
@@ -83,7 +83,6 @@ class Tab : public gfx::AnimationDelegate,
 
   // TabSlotView:
   void Layout() override;
-  const char* GetClassName() const override;
   bool OnKeyPressed(const ui::KeyEvent& event) override;
   bool OnKeyReleased(const ui::KeyEvent& event) override;
   bool OnMousePressed(const ui::MouseEvent& event) override;

chrome/browser/ui/views/tabs/tab_slot_view.cc

@@ -3,6 +3,10 @@
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/views/tabs/tab_slot_view.h"
+#include "ui/views/metadata/metadata_impl_macros.h"
 
 TabSlotView::TabSlotView() {}
 TabSlotView::~TabSlotView() {}
+
+BEGIN_METADATA(TabSlotView, views::View)
+END_METADATA

chrome/browser/ui/views/tabs/tab_slot_view.h

@@ -7,11 +7,14 @@
 
 #include "chrome/browser/ui/views/tabs/tab_strip_layout.h"
 #include "components/tab_groups/tab_group_id.h"
+#include "ui/views/metadata/metadata_header_macros.h"
 #include "ui/views/view.h"
 
 // View that can be laid out in the tabstrip.
 class TabSlotView : public views::View {
  public:
+  METADATA_HEADER(TabSlotView);
+
   enum class ViewType {
     kTab,
     kTabGroupHeader,

chrome/browser/ui/views/tabs/tab_strip.cc

@@ -94,6 +94,7 @@
 #include "ui/views/view_observer.h"
 #include "ui/views/view_targeter.h"
 #include "ui/views/view_targeter_delegate.h"
+#include "ui/views/view_utils.h"
 #include "ui/views/widget/root_view.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/window/non_client_view.h"
@@ -1984,8 +1985,7 @@ void TabStrip::OnMouseEventInTab(views::View* source,
   // Record time from cursor entering the tabstrip to first tap on a tab to
   // switch.
   if (mouse_entered_tabstrip_time_.has_value() &&
-      event.type() == ui::ET_MOUSE_PRESSED &&
-      !strcmp(source->GetClassName(), Tab::kViewClassName)) {
+      event.type() == ui::ET_MOUSE_PRESSED && views::IsViewClass<Tab>(source)) {
     UMA_HISTOGRAM_MEDIUM_TIMES(
         "TabStrip.TimeToSwitch",
         base::TimeTicks::Now() - mouse_entered_tabstrip_time_.value());
@@ -2426,7 +2426,7 @@ views::View* TabStrip::GetTooltipHandlerForPoint(const gfx::Point& point) {
     // Return any view that isn't a Tab or this TabStrip immediately. We don't
     // want to interfere.
     views::View* v = View::GetTooltipHandlerForPoint(point);
-    if (v && v != this && strcmp(v->GetClassName(), Tab::kViewClassName))
+    if (v && v != this && !views::IsViewClass<Tab>(v))
       return v;
 
     views::View* tab = FindTabHitByPoint(point);
@@ -3359,7 +3359,7 @@ void TabStrip::TabContextMenuController::ShowContextMenuForViewImpl(
     ui::MenuSourceType source_type) {
   // We are only intended to be installed as a context-menu handler for tabs, so
   // this cast should be safe.
-  DCHECK_EQ(Tab::kViewClassName, source->GetClassName());
+  DCHECK(views::IsViewClass<Tab>(source));
   Tab* const tab = static_cast<Tab*>(source);
   if (tab->closing())
     return;
@@ -3798,7 +3798,7 @@ views::View* TabStrip::TargetForRect(views::View* root, const gfx::Rect& rect) {
     // Return any view that isn't a Tab or this TabStrip immediately. We don't
     // want to interfere.
     views::View* v = views::ViewTargeterDelegate::TargetForRect(root, rect);
-    if (v && v != this && strcmp(v->GetClassName(), Tab::kViewClassName))
+    if (v && v != this && !views::IsViewClass<Tab>(v))
       return v;
 
     views::View* tab = FindTabHitByPoint(point);

chrome/browser/ui/views/tabs/tab_strip_unittest.cc

@@ -42,6 +42,7 @@
 #include "ui/views/view.h"
 #include "ui/views/view_class_properties.h"
 #include "ui/views/view_targeter.h"
+#include "ui/views/view_utils.h"
 #include "ui/views/widget/widget.h"
 
 namespace {
@@ -50,7 +51,7 @@ namespace {
 // found tab view, on NULL if none is found.
 views::View* FindTabView(views::View* view) {
   views::View* current = view;
-  while (current && strcmp(current->GetClassName(), Tab::kViewClassName)) {
+  while (current && !views::IsViewClass<Tab>(current)) {
     current = current->parent();
   }
   return current;

ui/views/BUILD.gn

@@ -241,6 +241,7 @@ component("views") {
     "view_targeter.h",
     "view_targeter_delegate.h",
     "view_tracker.h",
+    "view_utils.h",
     "views_delegate.h",
     "views_export.h",
     "views_features.h",

ui/views/view_utils.h

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_VIEWS_VIEW_UTILS_H_
+#define UI_VIEWS_VIEW_UTILS_H_
+
+#include <type_traits>
+
+#include "ui/views/metadata/metadata_types.h"
+#include "ui/views/view.h"
+
+namespace views {
+
+template <typename V>
+bool IsViewClass(View* view) {
+  static_assert(std::is_base_of<View, V>::value, "Only View classes supported");
+  metadata::ClassMetaData* parent = V::MetaData();
+  metadata::ClassMetaData* child = view->GetClassMetaData();
+  while (child && child != parent)
+    child = child->parent_class_meta_data();
+  return !!child;
+}
+
+}  // namespace views
+
+#endif  // UI_VIEWS_VIEW_UTILS_H_