Print Preview: Fix failure to save with long page title

chrome/browser/ui/webui/print_preview/print_preview_handler.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_handler.h"
 
 #include <ctype.h>
 #include <stddef.h>
 
 #include <map>
@@ skipping 1012 matching lines @@
         print_preview_ui()->initiator_title();
 
 #if defined(OS_WIN)
     base::FilePath::StringType print_job_title(print_job_title_utf16);
 #elif defined(OS_POSIX)
     base::FilePath::StringType print_job_title =
         base::UTF16ToUTF8(print_job_title_utf16);
 #endif
 
     base::i18n::ReplaceIllegalCharactersInPath(&print_job_title, '_');
-    base::FilePath default_filename(print_job_title);
+    // Take at most 251 characters - need 4 for the extension and max length

[Lei Zhang, 2017/04/05 20:06:07]

We may want to use PATH_MAX instead. On Windows there's MAX_PATH, but I don't
remember if PATH_MAX is portable across all platforms.

+    // on most platforms is 255.
+    base::FilePath default_filename(print_job_title.substr(0, 251));
     default_filename =
         default_filename.ReplaceExtension(FILE_PATH_LITERAL("pdf"));
 
     base::CommandLine* cmdline = base::CommandLine::ForCurrentProcess();
     bool prompt_user = !cmdline->HasSwitch(switches::kKioskModePrinting);
     SelectFile(default_filename, prompt_user);
   }
 }
 
 void PrintPreviewHandler::HandleHidePreview(const base::ListValue* /*args*/) {
@@ skipping 750 matching lines @@
 
 void PrintPreviewHandler::UnregisterForGaiaCookieChanges() {
   if (gaia_cookie_manager_service_)
     gaia_cookie_manager_service_->RemoveObserver(this);
 }
 
 void PrintPreviewHandler::SetPdfSavedClosureForTesting(
     const base::Closure& closure) {
   pdf_file_saved_closure_ = closure;
 }