GitLab

This CL:
* Fixes button spacing in the network details page.
* Fixes the on/off toggle button font and color for network and
  bluetooth
* Replaces incorrect primary/secondary button classes in dialogs
  with action/cancel-button
* Corrects the blue color for action buttons as per UX
* Converts the "add network" section to list-frame / list-item
  to correct borders and spacing.

BUG=710258,710259,710261
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2846763003
Cr-Commit-Position: refs/heads/master@{#468164}