Gallery: Add extern of analytics.js to Gallery.

BUG=None
TEST=None
TBR=kenobi@chromium.org

Review URL: https://codereview.chromium.org/942453003

Cr-Commit-Position: refs/heads/master@{#316996}

ui/file_manager/gallery/js/compiled_resources.gyp

@@ -98,6 +98,7 @@
           '<(CLOSURE_DIR)/externs/chrome_extensions.js',
           '<(CLOSURE_DIR)/externs/file_manager_private.js',
           '<(CLOSURE_DIR)/externs/metrics_private.js',
+          '../../../../third_party/analytics/externs.js',
           '../../externs/chrome_test.js',
           '../../externs/exif_entry.js',
           '../../externs/gallery_foreground.js',