Add a browser test that can communicate with the layout test framework and print pdfs.

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/files/file_path.h"

[Lei Zhang, 2014/07/17 21:08:16]

I don't think you need this since SetSelectedFileForTesting() just passes its
|path| without actually using it.

[ivandavid, 2014/07/17 22:27:47]

Done.

 #include "base/id_map.h"
 #include "base/lazy_instance.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/synchronization/lock.h"
 #include "base/values.h"
@@ skipping 584 matching lines @@
 }
 
 void PrintPreviewUI::OnPrintPreviewScalingDisabled() {
   web_ui()->CallJavascriptFunction("printScalingDisabledForSourcePDF");
 }
 
 // static
 void PrintPreviewUI::SetDelegateForTesting(TestingDelegate* delegate) {
   g_testing_delegate = delegate;
 }
+
+void PrintPreviewUI::SetSelectedFileForTesting(const base::FilePath& path) {
+  handler_->FileSelected(path, 0, NULL);
+}