Installing google-chrome in cloud build step not shared across steps (using volumes)

I'm having trouble installing google chrome that will be shareable across steps. My cloudbuild.yaml looks like so:

- name: 'ubuntu'
  args: ['bash', 'tools/download-chrome.sh']
  volumes:
  - name: 'bin'
    path: '/usr/bin'
- name: 'gcr.io/cloud-builders/npm'
  args: ['run', 'install-all-ci']
- name: 'gcr.io/cloud-builders/npm'
  args: ['test']
  volumes:
  - name: 'bin'
    path: '/usr/bin'

Where the first step downloads chrome, and calling which google-chrome returns /usr/bin/google-chrome. Doing the same in the last step returns nothing.