PDF Plugin: Add dummy JS compilation target.

- Uncomment line at third_party/closure_compiler/compiled_resources2.gyp:36
- Execute ./third_party/closure_compiler/run_compiler main

The dummy compilation target will facilitate the work needed to
fully type check the PDF Plugin's JS codebase.

BUG=721073
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2879543002
Cr-Commit-Position: refs/heads/master@{#472309}

chrome/browser/resources/pdf/compiled_resources2.gyp

+# Copyright 2017 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.
+{
+  'targets': [
+    {
+      'target_name': 'main',
+      'dependencies': [
+        # TODO(dpapad): Add dependencies here.
+      ],
+      'includes': ['../../../../third_party/closure_compiler/compile_js2.gypi'],
+    }
+  ],
+}

third_party/closure_compiler/compiled_resources2.gyp

@@ -35,8 +35,10 @@
         '<(DEPTH)/chrome/browser/resources/ntp4/compiled_resources2.gyp:*',
         '<(DEPTH)/chrome/browser/resources/offline_pages/compiled_resources2.gyp:*',
         '<(DEPTH)/chrome/browser/resources/options/compiled_resources2.gyp:*',
-        '<(DEPTH)/chrome/browser/resources/settings/compiled_resources2.gyp:*',
+        # TODO(dpapad): Uncomment following line as part of crbug.com/721073.
+        #'<(DEPTH)/chrome/browser/resources/pdf/compiled_resources2.gyp:*',
         '<(DEPTH)/chrome/browser/resources/print_preview/compiled_resources2.gyp:*',
+        '<(DEPTH)/chrome/browser/resources/settings/compiled_resources2.gyp:*',
         '<(DEPTH)/chrome/browser/resources/uber/compiled_resources2.gyp:*',
         '<(DEPTH)/chrome/browser/resources/webapks/compiled_resources2.gyp:*',
         '<(DEPTH)/ui/file_manager/compiled_resources2.gyp:*',