PrintPreview: Preview generation should not block print button.

chrome/browser/ui/webui/print_preview_handler.h

Index: chrome/browser/ui/webui/print_preview_handler.h
diff --git a/chrome/browser/ui/webui/print_preview_handler.h b/chrome/browser/ui/webui/print_preview_handler.h
index 02324691c708e85f692658e791b27467d2424527..c25528dc64f26f40d17ff003692a96269c8b6bb9 100644
--- a/chrome/browser/ui/webui/print_preview_handler.h
+++ b/chrome/browser/ui/webui/print_preview_handler.h
@@ -56,6 +56,10 @@ class PrintPreviewHandler : public WebUIMessageHandler,
   // First element of |args| is a job settings JSON string.
   void HandlePrint(const ListValue* args);
 
+  // Handles the request to hide the preview tab for printing.
+  // |args| is unused.
+  void HandleHidePreview(const ListValue* args);
+
   // Get the printer capabilities.
   // First element of |args| is the printer name.
   void HandleGetPrinterCapabilities(const ListValue* args);
@@ -94,6 +98,12 @@ class PrintPreviewHandler : public WebUIMessageHandler,
   // Adds all the recorded stats taken so far to histogram counts.
   void ReportStats();
 
+  // Helper function to hide the preview tab for printing.
+  void HidePreviewTab();
+
+  // Helper function to clear initiator tab details for this preview tab.
+  void ClearInitiatorTabDetails();
+
   // Pointer to current print system.
   scoped_refptr<printing::PrintBackend> print_backend_;