Add live updates for AshDevToolsCSSAgent

ash/common/devtools/ash_devtools_css_agent.h

Index: ash/common/devtools/ash_devtools_css_agent.h
diff --git a/ash/common/devtools/ash_devtools_css_agent.h b/ash/common/devtools/ash_devtools_css_agent.h
index c957da51e3e151bf025b9a7cd106a0e094e7874d..971524b9ad227cf75f820786a16bf69bc6e0da6b 100644
--- a/ash/common/devtools/ash_devtools_css_agent.h
+++ b/ash/common/devtools/ash_devtools_css_agent.h
@@ -7,13 +7,18 @@
 
 #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 WmWindowObserver,
+      public views::WidgetObserver,
+      public views::ViewObserver {
  public:
   explicit AshDevToolsCSSAgent(AshDevToolsDOMAgent* dom_agent);
   ~AshDevToolsCSSAgent() override;
@@ -24,9 +29,30 @@ class ASH_EXPORT AshDevToolsCSSAgent
       ui::devtools::protocol::Maybe<ui::devtools::protocol::CSS::CSSStyle>*
           inlineStyle) override;
 
+  // AshDevToolsDOMAgentObserver
+  void OnWindowAdded(WmWindow* window) override;
+  void OnWindowRemoved(WmWindow* window) override;
+  void OnWidgetAdded(views::Widget* widget) override;
+  void OnWidgetRemoved(views::Widget* widget) override;
+  void OnViewAdded(views::View* view) override;
+  void OnViewRemoved(views::View* view) override;
+
+  // WmWindowObserver
+  void OnWindowBoundsChanged(WmWindow* window,
+                             const gfx::Rect& old_bounds,
+                             const gfx::Rect& new_bounds) override;
+
+  // views::WidgetObserver
+  void OnWidgetBoundsChanged(views::Widget* widget,
+                             const gfx::Rect& new_bounds) override;
+
+  // views::ViewObserver
+  void OnViewBoundsChanged(views::View* view) override;
+
  private:
   std::unique_ptr<ui::devtools::protocol::CSS::CSSStyle> GetStylesForNode(
       int nodeId);
+  void InvalidateStyleSheet();
 
   AshDevToolsDOMAgent* dom_agent_;