Move BrowserPluginDelegate's lifetime mgmt out of content/

components/guest_view/renderer/guest_view_container.h

Index: components/guest_view/renderer/guest_view_container.h
diff --git a/components/guest_view/renderer/guest_view_container.h b/components/guest_view/renderer/guest_view_container.h
index 50b05cb886ab97832a4ed308c1c27c2ffff01c50..6cd1331c85d494be0a9afca14e1b15a20a454bf4 100644
--- a/components/guest_view/renderer/guest_view_container.h
+++ b/components/guest_view/renderer/guest_view_container.h
@@ -17,10 +17,12 @@ class GuestViewRequest;
 class GuestViewContainer : public content::BrowserPluginDelegate {
  public:
   explicit GuestViewContainer(content::RenderFrame* render_frame);
-  ~GuestViewContainer() override;
 
   static GuestViewContainer* FromID(int element_instance_id);
 
+  // Destroys this GuestViewContainer after performing necessary cleanup.
+  void Destroy() final;
+
   // IssueRequest queues up a |request| until the container is ready and
   // the browser process has responded to the last request if it's still
   // pending.
@@ -43,6 +45,13 @@ class GuestViewContainer : public content::BrowserPluginDelegate {
   // Called to perform actions when a GuestViewContainer gets a geometry.
   virtual void OnReady() {}
 
+  // Called to perform actions when a GuestViewContainer is about to be
+  // destroyed.
+  virtual void OnDestroy() {}
+
+ protected:
+  ~GuestViewContainer() override;
+
  private:
   class RenderFrameLifetimeObserver;
   friend class RenderFrameLifetimeObserver;
@@ -58,12 +67,14 @@ class GuestViewContainer : public content::BrowserPluginDelegate {
   // BrowserPluginDelegate implementation.
   void Ready() final;
   void SetElementInstanceID(int element_instance_id) final;
+  void WillDestroy() final;
 
   int element_instance_id_;
   content::RenderFrame* render_frame_;
   scoped_ptr<RenderFrameLifetimeObserver> render_frame_lifetime_observer_;
 
   bool ready_;
+  bool in_destruction_;
 
   std::deque<linked_ptr<GuestViewRequest> > pending_requests_;
   linked_ptr<GuestViewRequest> pending_response_;