Blimp Engine is based on Linux with USE_AURA, and its client is an Android app. It is desirable for end users to see the same Chrome Android external popup menu handling.

Thus, add USE_EXTERNAL_POPUP_MENU flag so that Blimp Engine can follow the same code path of the external Android popup menus before it reaches WebContentsView.

BUG=598764
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_site_isolation

Review-Url: https://codereview.chromium.org/1992393002
Cr-Commit-Position: refs/heads/master@{#397575}
19 files changed