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 <map>
 #include <set>
 #include <string>
@@ skipping 110 matching lines @@
     virtual void OnViewDestroyed() = 0;
 
    protected:
     virtual ~TouchEditingClient() {}
   };
 
   void set_touch_editing_client(TouchEditingClient* client) {
     touch_editing_client_ = client;
   }
 
-  explicit RenderWidgetHostViewAura(RenderWidgetHost* host);
+  RenderWidgetHostViewAura(RenderWidgetHost* host);
 
   // RenderWidgetHostView implementation.
   virtual void InitAsChild(gfx::NativeView parent_view) OVERRIDE;
   virtual RenderWidgetHost* GetRenderWidgetHost() const OVERRIDE;
   virtual void SetSize(const gfx::Size& size) OVERRIDE;
   virtual void SetBounds(const gfx::Rect& rect) OVERRIDE;
   virtual gfx::Vector2dF GetLastScrollOffset() const OVERRIDE;
   virtual gfx::NativeView GetNativeView() const OVERRIDE;
   virtual gfx::NativeViewId GetNativeViewId() const OVERRIDE;
   virtual gfx::NativeViewAccessible GetNativeViewAccessible() OVERRIDE;
@@ skipping 81 matching lines @@
   virtual gfx::AcceleratedWidget AccessibilityGetAcceleratedWidget() OVERRIDE;
   virtual gfx::NativeViewAccessible AccessibilityGetNativeViewAccessible()
       OVERRIDE;
   virtual bool LockMouse() OVERRIDE;
   virtual void UnlockMouse() OVERRIDE;
   virtual void OnSwapCompositorFrame(
       uint32 output_surface_id,
       scoped_ptr<cc::CompositorFrame> frame) OVERRIDE;
 
 #if defined(OS_WIN)
+  void SetLegacyRenderWidgetHostHWND(LegacyRenderWidgetHostHWND* legacy_hwnd);
   virtual void SetParentNativeViewAccessible(
       gfx::NativeViewAccessible accessible_parent) OVERRIDE;
   virtual gfx::NativeViewId GetParentForWindowlessPlugin() const OVERRIDE;
 #endif
 
   // Overridden from ui::TextInputClient:
   virtual void SetCompositionText(
       const ui::CompositionText& composition) OVERRIDE;
   virtual void ConfirmCompositionText() OVERRIDE;
   virtual void ClearCompositionText() OVERRIDE;
@@ skipping 77 matching lines @@
                            const gfx::Point& new_origin) OVERRIDE;
 
 #if defined(OS_WIN)
   // Sets the cutout rects from constrained windows. These are rectangles that
   // windowed NPAPI plugins shouldn't paint in. Overwrites any previous cutout
   // rects.
   void UpdateConstrainedWindowRects(const std::vector<gfx::Rect>& rects);
 
   // 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 223 matching lines @@
   // NPAPI plugins shouldn't draw over them.
   std::vector<gfx::Rect> constrained_rects_;
 
   typedef std::map<HWND, WebPluginGeometry> PluginWindowMoves;
   // Contains information about each windowed plugin's clip and cutout rects (
   // from the renderer). This is needed because when the transient windoiws
   // over this view changes, we need this information in order to create a new
   // region for the HWND.
   PluginWindowMoves plugin_window_moves_;
 
   // The LegacyRenderWidgetHostHWND class provides a dummy HWND which is used

[ananta, 2014/09/23 20:14:05]

Can you also add this comment in the WCVA class where it declares the
LegacyRenderWidgetHostHWND member?

[dmazzoni, 2014/09/24 22:57:51]

Done.

   // 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_;

[ananta, 2014/09/23 20:14:06]

Please remove this member.

[dmazzoni, 2014/09/24 22:57:51]

Done.

 #endif
 
   bool has_snapped_to_boundary_;
 
   TouchEditingClient* touch_editing_client_;
 
   scoped_ptr<OverscrollController> overscroll_controller_;
 
   // The last scroll offset of the view.
   gfx::Vector2dF last_scroll_offset_;
 
   gfx::Insets insets_;
 
   std::vector<ui::LatencyInfo> software_latency_info_;
 
   scoped_ptr<aura::client::ScopedTooltipDisabler> tooltip_disabler_;
 
   base::WeakPtrFactory<RenderWidgetHostViewAura> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewAura);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_AURA_H_