Print preview page selection should not require a rerendering of draft pages.

chrome/browser/ui/webui/print_preview_ui.h

Index: chrome/browser/ui/webui/print_preview_ui.h
diff --git a/chrome/browser/ui/webui/print_preview_ui.h b/chrome/browser/ui/webui/print_preview_ui.h
index 589f4414c79c6d8ddadde87675a2ba510291dd10..3dc6f6e0b1eefadddd5e46dc99fe2043cf101f7a 100644
--- a/chrome/browser/ui/webui/print_preview_ui.h
+++ b/chrome/browser/ui/webui/print_preview_ui.h
@@ -41,6 +41,10 @@ class PrintPreviewUI : public ChromeWebUI {
   // Clear the existing print preview data.
   void ClearAllPreviewData();
 
+  // Returns true if all the draft pages are available. |draft_page_count|
+  // specifies the total number of draft pages.
+  bool IsDraftPagesAvailable(int draft_page_count);
+
   // Setters
   void SetInitiatorTabURLAndTitle(const std::string& initiator_url,
                                   const string16& initiator_tab_title);
@@ -80,6 +84,8 @@ class PrintPreviewUI : public ChromeWebUI {
   void OnPreviewDataIsAvailable(int expected_pages_count,
                                 int preview_request_id);
 
+  // Notifies the Web UI renderer to reuse the preview data.
+  // |preview_request_id| indicates which request resulted in this response.
   void OnReusePreviewData(int preview_request_id);
 
   // Notifies the Web UI that preview tab is destroyed. This is the last chance