Summary:
We have 4 events:

buffer1 created
buffer2 created
buffer1 paramters sent
buffer2 paramters sent

Some are batched

We should connect to buffer 1's parameters being sent after the first
buffer is recieved, not in the potential event loop waiting for buffer
2.

Test Plan:
Passes locally
Haven't tested on build.k.o

Reviewers: #kwin

Subscribers: kde-frameworks-devel

Tags: #frameworks

Differential Revision: https://phabricator.kde.org/D19476