Revert "Remove notifications from PrintPreviewDialogController."

chrome/browser/printing/print_preview_dialog_controller.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 CHROME_BROWSER_PRINTING_PRINT_PREVIEW_DIALOG_CONTROLLER_H_
 #define CHROME_BROWSER_PRINTING_PRINT_PREVIEW_DIALOG_CONTROLLER_H_
 
-#include <vector>
+#include <map>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/sessions/session_id.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
 
 class GURL;
 
 namespace content {
 struct LoadCommittedDetails;
 class RenderProcessHost;
 class WebContents;
 }
 
 namespace printing {
 
 // For print preview, the WebContents that initiates the printing operation is
 // the initiator, and the constrained dialog that shows the print preview is the
 // print preview dialog.
 // This class manages print preview dialog creation and destruction, and keeps
 // track of the 1:1 relationship between initiator tabs and print preview
 // dialogs.
 class PrintPreviewDialogController
-    : public base::RefCounted<PrintPreviewDialogController> {
+    : public base::RefCounted<PrintPreviewDialogController>,
+      public content::NotificationObserver {
  public:
   PrintPreviewDialogController();
 
   static PrintPreviewDialogController* GetInstance();
 
   // Initiate print preview for |initiator|.
   // Call this instead of GetOrCreatePreviewDialog().
   static void PrintPreview(content::WebContents* initiator);
 
   // Get/Create the print preview dialog for |initiator|.
   // Exposed for unit tests.
   content::WebContents* GetOrCreatePreviewDialog(
       content::WebContents* initiator);
 
   // Returns the preview dialog for |contents|.
   // Returns |contents| if |contents| is a preview dialog.
   // Returns NULL if no preview dialog exists for |contents|.
   content::WebContents* GetPrintPreviewForContents(
       content::WebContents* contents) const;
 
   // Returns the initiator for |preview_dialog|.
   // Returns NULL if no initiator exists for |preview_dialog|.
   content::WebContents* GetInitiator(content::WebContents* preview_dialog);
 
   // Run |callback| on the dialog of each active print preview operation.
   void ForEachPreviewDialog(
       base::Callback<void(content::WebContents*)> callback);
 
+  // content::NotificationObserver implementation.
+  virtual void Observe(int type,
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
+
   // Returns true if |contents| is a print preview dialog.
   static bool IsPrintPreviewDialog(content::WebContents* contents);
 
   // Returns true if |url| is a print preview url.
   static bool IsPrintPreviewURL(const GURL& url);
 
   // Erase the initiator info associated with |preview_dialog|.
   void EraseInitiatorInfo(content::WebContents* preview_dialog);
 
   bool is_creating_print_preview_dialog() const {
     return is_creating_print_preview_dialog_;
   }
 
  private:
   friend class base::RefCounted<PrintPreviewDialogController>;
-  struct Operation;
+
+  // 1:1 relationship between a print preview dialog and its initiator tab.
+  // Key: Print preview dialog.
+  // Value: Initiator.
+  typedef std::map<content::WebContents*, content::WebContents*>
+      PrintPreviewDialogMap;
 
   virtual ~PrintPreviewDialogController();
 
-  // Handlers for observed events.
-  void OnRenderProcessExited(content::RenderProcessHost* rph);
+  // Handler for the RENDERER_PROCESS_CLOSED notification. This is observed when
+  // the initiator renderer crashed.
+  void OnRendererProcessClosed(content::RenderProcessHost* rph);
+
+  // Handler for the WEB_CONTENTS_DESTROYED notification. This is observed when
+  // either WebContents is closed.
   void OnWebContentsDestroyed(content::WebContents* contents);
-  void OnNavigationEntryCommitted(content::WebContents* contents,
-                                  const content::LoadCommittedDetails* details);
+
+  // Handler for the NAV_ENTRY_COMMITTED notification. This is observed when the
+  // renderer is navigated to a different page.
+  void OnNavEntryCommitted(content::WebContents* contents,
+                           content::LoadCommittedDetails* details);
 
   // Creates a new print preview dialog.
   content::WebContents* CreatePrintPreviewDialog(
       content::WebContents* initiator);
 
   // Helper function to store the title of the initiator associated with
   // |preview_dialog| in |preview_dialog|'s PrintPreviewUI.
   void SaveInitiatorTitle(content::WebContents* preview_dialog);
 
+  // Adds/Removes observers for notifications from |contents|.
+  void AddObservers(content::WebContents* contents);
+  void RemoveObservers(content::WebContents* contents);
+
   // Removes WebContents when they close/crash/navigate.
   void RemoveInitiator(content::WebContents* initiator);
   void RemovePreviewDialog(content::WebContents* preview_dialog);
 
-  // The list of the currently active preview operations.
-  std::vector<Operation*> preview_operations_;
+  // Mapping between print preview dialog and the corresponding initiator.
+  PrintPreviewDialogMap preview_dialog_map_;
+
+  // A registrar for listening to notifications.
+  content::NotificationRegistrar registrar_;
 
   // True if the controller is waiting for a new preview dialog via
   // content::NAVIGATION_TYPE_NEW_PAGE.
   bool waiting_for_new_preview_page_;
 
   // Whether the PrintPreviewDialogController is in the middle of creating a
   // print preview dialog.
   bool is_creating_print_preview_dialog_;
 
   DISALLOW_COPY_AND_ASSIGN(PrintPreviewDialogController);
 };
 
 }  // namespace printing
 
 #endif  // CHROME_BROWSER_PRINTING_PRINT_PREVIEW_DIALOG_CONTROLLER_H_