Add live updates for AshDevToolsCSSAgent

ash/common/devtools/ash_devtools_css_agent.h

 // Copyright 2016 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 ASH_COMMON_DEVTOOLS_ASH_DEVTOOLS_CSS_AGENT_H_
 #define ASH_COMMON_DEVTOOLS_ASH_DEVTOOLS_CSS_AGENT_H_
 
 #include "ash/common/devtools/ash_devtools_dom_agent.h"
 #include "components/ui_devtools/CSS.h"
+#include "ui/views/widget/widget_observer.h"
 
 namespace ash {
 namespace devtools {
 
 class ASH_EXPORT AshDevToolsCSSAgent
     : public NON_EXPORTED_BASE(ui::devtools::UiDevToolsBaseAgent<
-                               ui::devtools::protocol::CSS::Metainfo>) {
+                               ui::devtools::protocol::CSS::Metainfo>),
+      public AshDevToolsDOMAgentObserver {
  public:
   explicit AshDevToolsCSSAgent(AshDevToolsDOMAgent* dom_agent);
   ~AshDevToolsCSSAgent() override;
 
   // CSS::Backend
+  ui::devtools::protocol::Response enable() override;
+  ui::devtools::protocol::Response disable() override;
   ui::devtools::protocol::Response getMatchedStylesForNode(
-      int nodeId,
+      int node_id,
       ui::devtools::protocol::Maybe<ui::devtools::protocol::CSS::CSSStyle>*
-          inlineStyle) override;
+          inline_style) override;
+
+  // AshDevToolsDOMAgentObserver
+  void OnWindowBoundsChanged(WmWindow* window) override;
+  void OnWidgetBoundsChanged(views::Widget* widget) override;
+  void OnViewBoundsChanged(views::View* view) override;
 
  private:
   std::unique_ptr<ui::devtools::protocol::CSS::CSSStyle> GetStylesForNode(
-      int nodeId);
+      int node_id);
+  void InvalidateStyleSheet(int node_id);
 
   AshDevToolsDOMAgent* dom_agent_;
 
   DISALLOW_COPY_AND_ASSIGN(AshDevToolsCSSAgent);
 };
 
 }  // namespace devtools
 }  // namespace ash
 
 #endif  // ASH_COMMON_DEVTOOLS_ASH_DEVTOOLS_CSS_AGENT_H_