Show corresponding window/widget/view in UIElement tree when clicking on a UI element.

components/ui_devtools/views/ui_devtools_overlay_agent.h

+// Copyright 2017 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 COMPONENTS_UI_DEVTOOLS_VIEWS_UI_DEVTOOLS_OVERLAY_AGENT_H_
+#define COMPONENTS_UI_DEVTOOLS_VIEWS_UI_DEVTOOLS_OVERLAY_AGENT_H_
+
+#include "components/ui_devtools/Overlay.h"
+#include "components/ui_devtools/views/ui_devtools_dom_agent.h"
+#include "ui/events/event_handler.h"
+
+namespace ui_devtools {
+
+class UIDevToolsOverlayAgent : public ui_devtools::UiDevToolsBaseAgent<
+                                   ui_devtools::protocol::Overlay::Metainfo>,
+                               public UIDevToolsDOMAgentObserver,
+                               public ui::EventHandler {
+ public:
+  explicit UIDevToolsOverlayAgent(UIDevToolsDOMAgent* dom_agent);
+  ~UIDevToolsOverlayAgent() override;
+
+  // DOM::Backend:
+  ui_devtools::protocol::Response enable() override;
+  ui_devtools::protocol::Response disable() override;
+  ui_devtools::protocol::Response setInspectMode(
+      const String& in_mode,
+      protocol::Maybe<protocol::Overlay::HighlightConfig> in_highlightConfig)
+      override;
+  ui_devtools::protocol::Response highlightNode(
+      std::unique_ptr<ui_devtools::protocol::Overlay::HighlightConfig>
+          highlight_config,
+      ui_devtools::protocol::Maybe<int> node_id) override;
+  ui_devtools::protocol::Response hideHighlight() override;
+  void OnNodeBoundsChanged(int node_id) override;
+
+  // ui:EventHandler:
+  void OnMouseEvent(ui::MouseEvent* event) override;
+
+ private:
+  UIDevToolsDOMAgent* dom_agent_;
+
+  DISALLOW_COPY_AND_ASSIGN(UIDevToolsOverlayAgent);
+};
+
+}  // namespace ui_devtools
+
+#endif  // COMPONENTS_UI_DEVTOOLS_VIEWS_UI_DEVTOOLS_OVERLAY_AGENT_H_