Replace array() with [] and $this missing

Hii @joy29 Thank you for your contribution in particle responsive theme. i applied patch and its showing undefined $this variable.
here you used $this but you did not use messenger service here, I am moving this in Needs work, feel free to apply patch here.

------------------------------------------------------------------------------------
23 | WARNING | Variable $this is undefined.
29 | WARNING | Variable $this is undefined.
31 | WARNING | Variable $this is undefined.
35 | WARNING | Variable $this is undefined.
41 | WARNING | Variable $this is undefined.
43 | WARNING | Variable $this is undefined.
50 | WARNING | Variable $this is undefined.
56 | WARNING | Variable $this is undefined.
61 | WARNING | Variable $this is undefined.
66 | WARNING | Variable $this is undefined.
71 | WARNING | Variable $this is undefined.
88 | WARNING | Variable $this is undefined.
94 | WARNING | Variable $this is undefined.
96 | WARNING | Variable $this is undefined.
100 | WARNING | Variable $this is undefined.
105 | WARNING | Variable $this is undefined.
110 | WARNING | Variable $this is undefined.
115 | WARNING | Variable $this is undefined.
120 | WARNING | Variable $this is undefined.
128 | WARNING | Variable $this is undefined.
134 | WARNING | Variable $this is undefined.
136 | WARNING | Variable $this is undefined.
141 | WARNING | Variable $this is undefined.
146 | WARNING | Variable $this is undefined.
148 | WARNING | Variable $this is undefined.

Please review the code.

Thanks @DenisCi @karishmaamin @joy29 for your contribution. I commited changes in 8.x-4.x-dev , Will merge this in next release.