Create only a single LegacyRenderWidgetHostHWND per WebContentsViewAura.

content/browser/renderer_host/render_widget_host_view_aura.h

 // Copyright (c) 2012 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 CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_AURA_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_AURA_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 186 matching lines @@
   void ProcessMouseEvent(const blink::WebMouseEvent& event) override;
   void ProcessMouseWheelEvent(const blink::WebMouseWheelEvent& event) override;
   void ProcessTouchEvent(const blink::WebTouchEvent& event,
                          const ui::LatencyInfo& latency) override;
   void ProcessGestureEvent(const blink::WebGestureEvent& event,
                            const ui::LatencyInfo& latency) override;
   void TransformPointToLocalCoordSpace(const gfx::Point& point,
                                        cc::SurfaceId original_surface,
                                        gfx::Point* transformed_point) override;
 
+#if defined(OS_WIN)
+  void SetLegacyRenderWidgetHostHWND(LegacyRenderWidgetHostHWND* legacy_hwnd);
+#endif
+
   // Overridden from ui::TextInputClient:
   void SetCompositionText(const ui::CompositionText& composition) override;
   void ConfirmCompositionText() override;
   void ClearCompositionText() override;
   void InsertText(const base::string16& text) override;
   void InsertChar(const ui::KeyEvent& event) override;
   ui::TextInputType GetTextInputType() const override;
   ui::TextInputMode GetTextInputMode() const override;
   int GetTextInputFlags() const override;
   bool CanComposeInline() const override;
@@ skipping 62 matching lines @@
   // Overridden from aura::WindowTreeHostObserver:
   void OnHostMoved(const aura::WindowTreeHost* host,
                    const gfx::Point& new_origin) override;
 
 #if defined(OS_WIN)
   // Gets the HWND of the host window.
   HWND GetHostWindowHWND() const;
 
   // Updates the cursor clip region. Used for mouse locking.
   void UpdateMouseLockRegion();
-
-  // Notification that the LegacyRenderWidgetHostHWND was destroyed.
-  void OnLegacyWindowDestroyed();
 #endif
 
   // Method to indicate if this instance is shutting down or closing.
   // TODO(shrikant): Discuss around to see if it makes sense to add this method
   // as part of RenderWidgetHostView.
   bool IsClosing() const { return in_shutdown_; }
 
   // Sets whether the overscroll controller should be enabled for this page.
   void SetOverscrollControllerEnabled(bool enabled);
 
@@ skipping 314 matching lines @@
     VISIBLE,
     NOT_VISIBLE,
   };
   CursorVisibilityState cursor_visibility_state_in_renderer_;
 
 #if defined(OS_WIN)
   // The LegacyRenderWidgetHostHWND class provides a dummy HWND which is used
   // for accessibility, as the container for windowless plugins like
   // Flash/Silverlight, etc and for legacy drivers for trackpoints/trackpads,
   // etc.
-  // The LegacyRenderWidgetHostHWND instance is created during the first call
-  // to RenderWidgetHostViewAura::InternalSetBounds. The instance is destroyed
-  // when the LegacyRenderWidgetHostHWND hwnd is destroyed.
   content::LegacyRenderWidgetHostHWND* legacy_render_widget_host_HWND_;
 
-  // Set to true if the legacy_render_widget_host_HWND_ instance was destroyed
-  // by Windows. This could happen if the browser window was destroyed by
-  // DestroyWindow for e.g. This flag helps ensure that we don't try to create
-  // the LegacyRenderWidgetHostHWND instance again as that would be a futile
-  // exercise.
-  bool legacy_window_destroyed_;
-
   // Contains a copy of the last context menu request parameters. Only set when
   // we receive a request to show the context menu on a long press.
   std::unique_ptr<ContextMenuParams> last_context_menu_params_;
 #endif
 
   bool has_snapped_to_boundary_;
 
   std::unique_ptr<TouchSelectionControllerClientAura>
       selection_controller_client_;
   std::unique_ptr<ui::TouchSelectionController> selection_controller_;
@@ skipping 25 matching lines @@
   bool disable_input_event_router_for_testing_;
 
   base::WeakPtrFactory<RenderWidgetHostViewAura> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewAura);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_AURA_H_