PDF viewer: Autogenerate externs

Autogenerate the resources_private.js externs file, and update
pdf_viewer.js to use an enum from the new autogenerated file.

Bug: 721073
Change-Id: I177d3b229f27555bf811abc7087321606f412fdd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1811499
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#699974}

chrome/browser/resources/pdf/pdf_viewer.js

@@ -416,7 +416,8 @@ class PDFViewer {
 
     // Request translated strings.
     chrome.resourcesPrivate.getStrings(
-        'pdf', strings => this.handleStrings_(strings));
+        chrome.resourcesPrivate.Component.PDF,
+        strings => this.handleStrings_(strings));
 
     // Listen for save commands from the browser.
     if (chrome.mimeHandlerPrivate && chrome.mimeHandlerPrivate.onSave) {

chrome/common/extensions/api/PRESUBMIT.py

@@ -35,6 +35,7 @@ def _CheckExterns(input_api, output_api):
     'file_system_provider.idl': 'file_system_provider.js',
     'language_settings_private.idl': 'language_settings_private.js',
     'passwords_private.idl': 'passwords_private.js',
+    'resources_private.idl': 'resources_private.js',
     'safe_browsing_private.idl': 'safe_browsing_private.js',
     'system_private.json': 'system_private.js',
     'users_private.idl': 'users_private.js',

third_party/closure_compiler/externs/resources_private.js

@@ -2,15 +2,37 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// This file was generated by:
+//   tools/json_schema_compiler/compiler.py.
+// NOTE: The format of types has changed. 'FooType' is now
+//   'chrome.resourcesPrivate.FooType'.
+// Please run the closure compiler before committing changes.
+// See https://chromium.googlesource.com/chromium/src/+/master/docs/closure_compilation.md
+
+/** @fileoverview Externs generated from namespace: resourcesPrivate */
+
 /**
  * @const
  */
 chrome.resourcesPrivate = {};
 
 /**
- * Records a value than can range from 1 to 1,000,000.
- * @param {string} component
- * @param {!function(Object)} callback Callback to handle the dictionary of
- *     localized strings for |component|.
+ * @enum {string}
+ */
+chrome.resourcesPrivate.Component = {
+  IDENTITY: 'identity',
+  PDF: 'pdf',
+};
+
+/**
+ * Gets localized strings for a component extension. Includes default WebUI
+ * loadTimeData values for text and language settings (fontsize, fontfamily,
+ * language, textdirection). See
+ * chrome/browser/extensions/api/resources_private/resources_private_api.cc for
+ * instructions on adding a new component to this API.
+ * @param {!chrome.resourcesPrivate.Component} component Internal chrome
+ *     component to get strings for.
+ * @param {function(Object):void} callback Called with a dictionary mapping
+ *     names to strings.
  */
 chrome.resourcesPrivate.getStrings = function(component, callback) {};