PrintPreview: Preview generation should not block print button.

chrome/browser/ui/webui/print_preview_ui.cc

 // Copyright (c) 2011 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/ui/webui/print_preview_ui.h"
 
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/values.h"
 #include "chrome/browser/printing/print_preview_data_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/webui/print_preview_data_source.h"
 #include "chrome/browser/ui/webui/print_preview_handler.h"
 #include "content/browser/tab_contents/tab_contents.h"
 
 PrintPreviewUI::PrintPreviewUI(TabContents* contents)
     : ChromeWebUI(contents),
-      initial_preview_start_time_(base::TimeTicks::Now()) {
+      initial_preview_start_time_(base::TimeTicks::Now()),
+      is_tab_hidden_for_print_(false) {
   // PrintPreviewUI owns |handler|.
   PrintPreviewHandler* handler = new PrintPreviewHandler();
   AddMessageHandler(handler->Attach(this));
 
   // Set up the chrome://print/ data source.
   contents->profile()->GetChromeURLDataManager()->AddDataSource(
       new PrintPreviewDataSource());
 
   // Store the PrintPreviewUIAddress as a string.
   // "0x" + deadc0de + '\0' = 2 + 2 * sizeof(this) + 1;
@@ skipping 36 matching lines @@
   StringValue title(job_title);
   FundamentalValue is_preview_modifiable(modifiable);
   StringValue ui_identifier(preview_ui_addr_str_);
   CallJavascriptFunction("updatePrintPreview", pages_count, title,
                          is_preview_modifiable, ui_identifier);
 }
 
 PrintPreviewDataService* PrintPreviewUI::print_preview_data_service() {
   return PrintPreviewDataService::GetInstance();
 }