It would be useful for the Constellation is ever going to store data
per-WebView for the purposes of making cleanup and resource management
easier. If that's ever going to happen the `WebView` needs to be passed
with all messages that need it. This change makes it so that messages to
the Constellation that require a Pipeline also carry a WebViewId. This
eliminates one way in which message handling might go wrong.
This avoids making the Constelaltion look up the `WebViewId` for many
messages
that it receives.
Testing: This should not change observable behavior, so should be
covered by existing tests.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
148ce3e9c7