Fix print preview close in gmail.

chrome/browser/printing/print_preview_dialog_controller.cc

 // 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.
 
 #include "chrome/browser/printing/print_preview_dialog_controller.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <string>
@@ skipping 300 matching lines @@
 }
 
 void PrintPreviewDialogController::OnNavEntryCommitted(
     WebContents* contents, content::LoadCommittedDetails* details) {
   WebContents* preview_dialog = GetPrintPreviewForContents(contents);
   if (!preview_dialog) {
     NOTREACHED();
     return;
   }
 
+  if (details) {

[Lei Zhang, 2016/07/30 00:36:30]

Isn't this handling navigation for both the initiator and the preview
WebContents? Should it only handle the initiator's navigation? In which case,
this probably should come after the "if (contents == preview_dialog)" block
below.

[rbpotter, 2016/07/30 01:06:44]

When the gmail auto-navigation happens, the contents == preview_dialog block
below never gets hit, which is why RemoveInitiator is called at the end of the
function. So contents != preview_dialog  for this case, which is why I put the
logic here. Not sure why this is the case though - any thoughts ?

[rbpotter, 2016/07/30 01:20:18]

Done.

+    ui::PageTransition type = details->entry->GetTransitionType();
+    content::NavigationType nav_type = details->type;
+    if (nav_type == content::NAVIGATION_TYPE_EXISTING_PAGE &&

[rbpotter, 2016/07/30 00:03:49]

This condition covers the case that appears for the gmail update transition. I
have tested several other possible page transitions (e.g. navigating to a new
page, hitting refresh, navigating to a new tab via a link from print preview's
New Tab preview page, and manually making changes to the URL in gmail) that
should trigger a print preview close, and these all still work. Let me know if
you can think of a specific case that should trigger a print preview close that
might have a false positive here, and I will test.

+        (ui::PageTransitionCoreTypeIs(type, ui::PAGE_TRANSITION_TYPED) ||
+         ui::PageTransitionCoreTypeIs(type, ui::PAGE_TRANSITION_LINK)))
+      return;
+  }
   if (contents == preview_dialog) {
     // Preview dialog navigated.
     if (details) {
       ui::PageTransition transition_type =
           details->entry->GetTransitionType();
       content::NavigationType nav_type = details->type;
 
       // New |preview_dialog| is created. Don't update/erase map entry.
       if (waiting_for_new_preview_page_ &&
           ui::PageTransitionCoreTypeIs(transition_type,
@@ skipping 128 matching lines @@
   if (initiator) {
     RemoveObservers(initiator);
     PrintViewManager::FromWebContents(initiator)->PrintPreviewDone();
   }
 
   preview_dialog_map_.erase(preview_dialog);
   RemoveObservers(preview_dialog);
 }
 
 }  // namespace printing