GitLab

Fixes a MacViewsBrowser link error after r397320, starting at
http://go/macviewsbuilder/builds/11045, like

Undefined symbols for architecture x86_64:
  "ChromeExtensionChooserDialog::ShowDialog(ChooserController*) const", referenced from:
      ChromeExtensionBluetoothChooser::ChromeExtensionBluetoothChooser

MacViewsBrowser needs a ShowDialog() symbol, which will provide the
toolkit-views implementation when it's ready.

BUG=425229, 613638
TBR=juncai@chromium.org

Review-Url: https://codereview.chromium.org/2036033003
Cr-Commit-Position: refs/heads/master@{#397911}