Factor out RenderWidgetHostConnector

content/browser/renderer_host/render_widget_host_view_android.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_ANDROID_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_ANDROID_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 60 matching lines @@
       public content::TextInputManager::Observer,
       public ui::DelegatedFrameHostAndroid::Client,
       public cc::BeginFrameObserver {
  public:
   RenderWidgetHostViewAndroid(RenderWidgetHostImpl* widget,
                               ContentViewCoreImpl* content_view_core);
   ~RenderWidgetHostViewAndroid() override;
 
   void Blur();
 
+  // Interface used to observe the destruction of a RenderWidgetHostViewAndroid.
+  class DestructionObserver {
+   public:
+    virtual void RenderWidgetHostViewDestroyed(
+        RenderWidgetHostViewAndroid* rwhva) = 0;
+
+   protected:
+    virtual ~DestructionObserver() {}
+  };
+
+  void AddDestructionObserver(DestructionObserver* connector);
+  void RemoveDestructionObserver(DestructionObserver* connector);
+
   // RenderWidgetHostView implementation.
   bool OnMessageReceived(const IPC::Message& msg) override;
   void InitAsChild(gfx::NativeView parent_view) override;
   void InitAsPopup(RenderWidgetHostView* parent_host_view,
                    const gfx::Rect& pos) override;
   void InitAsFullscreen(RenderWidgetHostView* reference_host_view) override;
   RenderWidgetHost* GetRenderWidgetHost() const override;
   void SetSize(const gfx::Size& size) override;
   void SetBounds(const gfx::Rect& rect) override;
   gfx::Vector2dF GetLastScrollOffset() const override;
@@ skipping 306 matching lines @@
 
   // The last scroll offset of the view.
   gfx::Vector2dF last_scroll_offset_;
 
   float prev_top_shown_pix_;
   float prev_bottom_shown_pix_;
 
   cc::mojom::MojoCompositorFrameSinkClient* renderer_compositor_frame_sink_ =
       nullptr;
 
+  std::list<DestructionObserver*> destruction_observers_;

[boliu, 2017/04/14 01:10:07]

nit: vector is generally more memory efficient and probably also faster than
linked list

[Jinsuk Kim, 2017/04/14 02:16:33]

Done.

+
   base::WeakPtrFactory<RenderWidgetHostViewAndroid> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewAndroid);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_ANDROID_H_