Fix Print Preview Alt + Left Arrow breakage

chrome/browser/printing/print_preview_dialog_controller.h

Index: chrome/browser/printing/print_preview_dialog_controller.h
diff --git a/chrome/browser/printing/print_preview_dialog_controller.h b/chrome/browser/printing/print_preview_dialog_controller.h
index c89954e5628a6c9c22de206ea17b3c4fd1a3e901..6710e8ec79d536e32959da05a709453fc63054b1 100644
--- a/chrome/browser/printing/print_preview_dialog_controller.h
+++ b/chrome/browser/printing/print_preview_dialog_controller.h
@@ -44,7 +44,7 @@ class PrintPreviewDialogController
 
   // Get/Create the print preview dialog for |initiator|.
   // Exposed for unit tests.
-  content::WebContents* GetOrCreatePreviewDialog(
+  virtual content::WebContents* GetOrCreatePreviewDialog(
       content::WebContents* initiator);
 
   // Returns the preview dialog for |contents|.
@@ -79,8 +79,9 @@ class PrintPreviewDialogController
     return is_creating_print_preview_dialog_;
   }
 
- private:
-  friend class base::RefCounted<PrintPreviewDialogController>;
+ protected:
+ // Moved to this category so that testing subclass works

[Lei Zhang, 2016/08/17 21:27:54]

No need for the comment in the code to check in. Maybe just write a comment in
code review instead next time?

+  ~PrintPreviewDialogController() override;
 
   // 1:1 relationship between a print preview dialog and its initiator tab.
   // Key: Print preview dialog.
@@ -88,8 +89,16 @@ class PrintPreviewDialogController
   using PrintPreviewDialogMap =
       std::map<content::WebContents*, content::WebContents*>;
 
-  ~PrintPreviewDialogController() override;
+  // Mapping between print preview dialog and the corresponding initiator.
+  PrintPreviewDialogMap preview_dialog_map_;

[Lei Zhang, 2016/08/17 21:27:54]

Can we provide a setter method instead? Keep the member variable private.

+  virtual void RemoveInitiator(content::WebContents* initiator);
+
+  // Adds/removes observers for notifications from |contents|.
+  void AddObservers(content::WebContents* contents);
+  void RemoveObservers(content::WebContents* contents);
 
+ private:
+  friend class base::RefCounted<PrintPreviewDialogController>;
   // Handler for the RENDERER_PROCESS_CLOSED notification. This is observed when
   // the initiator renderer crashed.
   void OnRendererProcessClosed(content::RenderProcessHost* rph);
@@ -111,17 +120,9 @@ class PrintPreviewDialogController
   // |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);
 
-  // Mapping between print preview dialog and the corresponding initiator.
-  PrintPreviewDialogMap preview_dialog_map_;
-
   // A registrar for listening to notifications.
   content::NotificationRegistrar registrar_;