Print preview: Display a dummy page when a user visits chrome://print directly.

chrome/browser/ui/webui/print_preview_data_source.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_data_source.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/message_loop.h"
@@ skipping 18 matching lines @@
 // U+0028 U+21E7 U+2318 U+0050 U+0029 in UTF8
 const char kAdvancedPrintShortcut[] = "\x28\xE2\x8c\xA5\xE2\x8C\x98\x50\x29";
 #elif defined(OS_WIN)
 const char kAdvancedPrintShortcut[] = "(Ctrl+Shift+P)";
 #else
 const char kAdvancedPrintShortcut[] = "(Shift+Ctrl+P)";
 #endif
 
 };  // namespace
 
-PrintPreviewDataSource::PrintPreviewDataSource()
+PrintPreviewDataSource::PrintPreviewDataSource(bool is_dummy)
     : ChromeWebUIDataSource(chrome::kChromeUIPrintHost) {
+  Init(is_dummy);
+}
+
+void PrintPreviewDataSource::Init(bool is_dummy) {
+  if (is_dummy) {
+    AddLocalizedString("intentionallyBlankText",
+                       IDS_PRINT_PREVIEW_INTENTIONALLY_BLANK);
+  }
 
   AddLocalizedString("title", IDS_PRINT_PREVIEW_TITLE);
   AddLocalizedString("loading", IDS_PRINT_PREVIEW_LOADING);
 #if defined(GOOGLE_CHROME_BUILD)
   AddString("noPlugin", l10n_util::GetStringFUTF16(
       IDS_PRINT_PREVIEW_NO_PLUGIN, ASCIIToUTF16("chrome://plugins/")));
 #else
   AddLocalizedString("noPlugin", IDS_PRINT_PREVIEW_NO_PLUGIN);
 #endif
   AddLocalizedString("launchNativeDialog", IDS_PRINT_PREVIEW_NATIVE_DIALOG);
@@ skipping 74 matching lines @@
   AddLocalizedString("noMargins", IDS_PRINT_PREVIEW_NO_MARGINS);
   AddLocalizedString("customMargins", IDS_PRINT_PREVIEW_CUSTOM_MARGINS);
   AddLocalizedString("minimumMargins", IDS_PRINT_PREVIEW_MINIMUM_MARGINS);
   AddLocalizedString("top", IDS_PRINT_PREVIEW_TOP_MARGIN_LABEL);
   AddLocalizedString("bottom", IDS_PRINT_PREVIEW_BOTTOM_MARGIN_LABEL);
   AddLocalizedString("left", IDS_PRINT_PREVIEW_LEFT_MARGIN_LABEL);
   AddLocalizedString("right", IDS_PRINT_PREVIEW_RIGHT_MARGIN_LABEL);
 
   set_json_path("strings.js");
   add_resource_path("print_preview.js", IDR_PRINT_PREVIEW_JS);
-  set_default_resource(IDR_PRINT_PREVIEW_HTML);
+  set_default_resource(
+      is_dummy ? IDR_PRINT_PREVIEW_HTML_DUMMY : IDR_PRINT_PREVIEW_HTML);
 }
 
 PrintPreviewDataSource::~PrintPreviewDataSource() {
 }
 
 void PrintPreviewDataSource::StartDataRequest(const std::string& path,
                                               bool is_incognito,
                                               int request_id) {
   // Parent class handles most requests except for the print preview data.
   if (!EndsWith(path, "/print.pdf", true)) {
     ChromeWebUIDataSource::StartDataRequest(path, is_incognito, request_id);
     return;
   }
 
   // Print Preview data.
   scoped_refptr<RefCountedBytes> data;
   std::vector<std::string> url_substr;
   base::SplitString(path, '/', &url_substr);
   int page_index = 0;
   if (url_substr.size() == 3 && base::StringToInt(url_substr[1], &page_index)) {
-      PrintPreviewDataService::GetInstance()->GetDataEntry(
-          url_substr[0], page_index, &data);
+    PrintPreviewDataService::GetInstance()->GetDataEntry(
+        url_substr[0], page_index, &data);
   }
   if (data.get()) {
     SendResponse(request_id, data);
     return;
   }
   // Invalid request.
   scoped_refptr<RefCountedBytes> empty_bytes(new RefCountedBytes);
   SendResponse(request_id, empty_bytes);
 }