Added basic browser test for window.print() from Chrome apps.

chrome/browser/ui/webui/print_preview/print_preview_ui.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/ui/webui/print_preview/print_preview_ui.h"
 
 #include <map>
 
 #include "base/id_map.h"
 #include "base/lazy_instance.h"
@@ skipping 502 matching lines @@
 
   if (!initial_preview_start_time_.is_null()) {
     UMA_HISTOGRAM_TIMES("PrintPreview.InitialDisplayTime",
                         base::TimeTicks::Now() - initial_preview_start_time_);
     UMA_HISTOGRAM_COUNTS("PrintPreview.PageCount.Initial",
                          expected_pages_count);
     initial_preview_start_time_ = base::TimeTicks();
   }
   base::FundamentalValue ui_identifier(id_);
   base::FundamentalValue ui_preview_request_id(preview_request_id);
-  web_ui()->CallJavascriptFunction("updatePrintPreview", ui_identifier,
-                                   ui_preview_request_id);
+  if (AutoCancelForTesting()) {
+    OnClosePrintPreviewDialog();
+  } else {
+    web_ui()->CallJavascriptFunction("updatePrintPreview", ui_identifier,
+                                     ui_preview_request_id);
+  }
 }
 
 void PrintPreviewUI::OnPrintPreviewDialogDestroyed() {
   handler_->OnPrintPreviewDialogDestroyed();
 }
 
 void PrintPreviewUI::OnFileSelectionCancelled() {
   web_ui()->CallJavascriptFunction("fileSelectionCancelled");
 }
 
@@ skipping 40 matching lines @@
   delegate->OnDialogCloseFromWebUI();
 }
 
 void PrintPreviewUI::OnReloadPrintersList() {
   web_ui()->CallJavascriptFunction("reloadPrintersList");
 }
 
 void PrintPreviewUI::OnPrintPreviewScalingDisabled() {
   web_ui()->CallJavascriptFunction("printScalingDisabledForSourcePDF");
 }
+
+static bool g_auto_cancel_for_testing_ = false;
+
+void PrintPreviewUI::SetAutoCancelForTesting(bool auto_cancel) {
+  g_auto_cancel_for_testing_ = auto_cancel;
+}
+
+bool PrintPreviewUI::AutoCancelForTesting() {
+  return g_auto_cancel_for_testing_;
+}