Fix print preview close in gmail.

Print preview closed in gmail when gmail navigated to a new
URL fragment. This occurred if print preview was requested
just after making changes to an e-mail draft in a compose
message window. Added check that will ensure print preview
remains open in this case.

BUG= 614998

Review-Url: https://codereview.chromium.org/2201543002
Cr-Commit-Position: refs/heads/master@{#408860}

chrome/browser/printing/print_preview_dialog_controller.cc

@@ -347,6 +347,14 @@ void PrintPreviewDialogController::OnNavEntryCommitted(
     NOTREACHED();
     return;
   }
+  if (details) {
+    ui::PageTransition type = details->entry->GetTransitionType();
+    content::NavigationType nav_type = details->type;
+    if (nav_type == content::NAVIGATION_TYPE_EXISTING_PAGE &&
+        (ui::PageTransitionCoreTypeIs(type, ui::PAGE_TRANSITION_TYPED) ||
+         ui::PageTransitionCoreTypeIs(type, ui::PAGE_TRANSITION_LINK)))
+      return;
+  }
 
   RemoveInitiator(contents);
 }