Implement <webview> droplink event
In the Chrome signin page, we expect it to be possible to navigate on dragging URLs
from outside of the content area into the content area. In <webview>, we do not wish
to navigate the <webview> on link drop but the embedder. Currently navigation on drop
is disabled within a <webview>. This CL provides a droplink event that the embedder can
listen to and navigate when a link is dropped into a <webview> from outside of its
bounds.
Note that this behavior is not identical to other Chrome tabs. In other tabs, if a link is dropped onto
a drop target, the page will not navigate. In this implementation, any external link drop will fire the droplink
event. This is probably not important for the signin
page however because no fields expect to take in links there. The plumbing in this patch
is less disruptive so I'll leave at that unless there is a pressing need to plumb the
navigation decision out of the guest Blink instance and up into the embedder.
BUG=460757
Review URL: https://codereview.chromium.org/945333002
Cr-Commit-Position: refs/heads/master@{#317740}
11 files changed
