Implement lifetime observer on RenderWidgetHostViewBase.

content/browser/renderer_host/render_widget_host_input_event_router.h

 // Copyright 2015 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_INPUT_EVENT_ROUTER_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_INPUT_EVENT_ROUTER_H_
 
 #include <stdint.h>
 #include <unordered_map>
 
 #include "base/containers/hash_tables.h"
 #include "base/macros.h"
-#include "base/memory/weak_ptr.h"
 #include "cc/surfaces/surface_hittest_delegate.h"
 #include "cc/surfaces/surface_id.h"
+#include "content/browser/renderer_host/render_widget_host_view_base_observer.h"
 #include "content/common/content_export.h"
 
 struct FrameHostMsg_HittestData_Params;
 
 namespace blink {
 class WebMouseEvent;
 class WebMouseWheelEvent;
 class WebTouchEvent;
 }
 
 namespace gfx {
 class Point;
 }
 
 namespace ui {
 class LatencyInfo;
 }
 
 namespace content {
 
 class RenderWidgetHostViewBase;
 
 // Class owned by WebContentsImpl for the purpose of directing input events
 // to the correct RenderWidgetHost on pages with multiple RenderWidgetHosts.
 // It maintains a mapping of RenderWidgetHostViews to Surface IDs that they
 // own. When an input event requires routing based on window coordinates,
 // this class requests a Surface hit test from the provided |root_view| and
 // forwards the event to the owning RWHV of the returned Surface ID.
-class CONTENT_EXPORT RenderWidgetHostInputEventRouter {
+class CONTENT_EXPORT RenderWidgetHostInputEventRouter
+    : public RenderWidgetHostViewBaseObserver {
  public:
   RenderWidgetHostInputEventRouter();
-  ~RenderWidgetHostInputEventRouter();
+  ~RenderWidgetHostInputEventRouter() final;
+
+  void OnRenderWidgetHostViewBaseDestroyed(
+      RenderWidgetHostViewBase* view) override;
 
   void RouteMouseEvent(RenderWidgetHostViewBase* root_view,
                        blink::WebMouseEvent* event);
   void RouteMouseWheelEvent(RenderWidgetHostViewBase* root_view,
                             blink::WebMouseWheelEvent* event);
   void RouteTouchEvent(RenderWidgetHostViewBase* root_view,
                        blink::WebTouchEvent *event,
                        const ui::LatencyInfo& latency);
 
   void AddSurfaceIdNamespaceOwner(uint32_t id, RenderWidgetHostViewBase* owner);
@@ skipping 17 matching lines @@
             hittest_data);
     bool RejectHitTarget(const cc::SurfaceDrawQuad* surface_quad,
                          const gfx::Point& point_in_quad_space) override;
     bool AcceptHitTarget(const cc::SurfaceDrawQuad* surface_quad,
                          const gfx::Point& point_in_quad_space) override;
 
     const std::unordered_map<cc::SurfaceId, HittestData, cc::SurfaceIdHash>&
         hittest_data_;
   };
 
-  using WeakTarget = base::WeakPtr<RenderWidgetHostViewBase>;
   using SurfaceIdNamespaceOwnerMap =
-      base::hash_map<uint32_t, base::WeakPtr<RenderWidgetHostViewBase>>;
+      base::hash_map<uint32_t, RenderWidgetHostViewBase*>;
+
+  void ClearAllObserverRegistrations();
 
   RenderWidgetHostViewBase* FindEventTarget(RenderWidgetHostViewBase* root_view,
                                             const gfx::Point& point,
                                             gfx::Point* transformed_point);
 
   SurfaceIdNamespaceOwnerMap owner_map_;
-  WeakTarget current_touch_target_;
+  RenderWidgetHostViewBase* current_touch_target_;
   int active_touches_;
   std::unordered_map<cc::SurfaceId, HittestData, cc::SurfaceIdHash>
       hittest_data_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostInputEventRouter);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_INPUT_EVENT_ROUTER_H_