Generate externs/file_system_provider.js

Command line:

python tools/json_schema_compiler/compiler.py \
  chrome/common/extensions/api/file_system_provider.idl \
  --root=. --generator=externs \
  > third_party/closure_compiler/externs/file_system_provider.js

Bug: 613096
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I146dd9125ee575e7ea6592cf6805a5f9eec194b7
Reviewed-on: https://chromium-review.googlesource.com/1089595Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Commit-Queue: Nigel Tao <nigeltao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565481}

chrome/common/extensions/api/PRESUBMIT.py

@@ -32,6 +32,7 @@ def _CheckExterns(input_api, output_api):
     'bookmark_manager_private.json': 'bookmark_manager_private.js',
     'command_line_private.json': 'command_line_private.js',
     'file_manager_private.idl': 'file_manager_private.js',
+    'file_system_provider.idl': 'file_system_provider.js',
     'language_settings_private.idl': 'language_settings_private.js',
     'passwords_private.idl': 'passwords_private.js',
     'safe_browsing_private.idl': 'safe_browsing_private.js',