GitLab

This CL implements recommendations from a Desktop PWA UI review.
 - Use "Install <app>..." instead of "Add <app> to shelf..." for PWAs.
   Before: https://bugs.chromium.org/p/chromium/issues/attachment?aid=331947&signed_aid=9D-HKXE7gYd0wUpreYCSAg==&inline=1
   After: https://bugs.chromium.org/p/chromium/issues/attachment?aid=331948&signed_aid=cDTnW4abw74CAZfks6FXkw==&inline=1
 - Use "Create shortcut" instead of "Add to <shortcut container>" for non-PWAs.
   Before: https://bugs.chromium.org/p/chromium/issues/attachment?aid=331943&signed_aid=Ok3VbYPcM5cA0kp1mufUcQ==&inline=1
   After: https://bugs.chromium.org/p/chromium/issues/attachment?aid=331944&signed_aid=Jn3zF1Bjunr7NY6U5HZs-Q==&inline=1

In addition to these changes the confirmation dialog for these actions
have been updated for consistency:
 - For PWAs:
   Use "Install app?" instead of "Add to shelf?" for the title.
   Use "Install" instead of "Add" for the button.
   Before: https://bugs.chromium.org/p/chromium/issues/attachment?aid=331949&signed_aid=NBRq_H4GTrT_Nlj4uJZUgg==&inline=1
   After: https://bugs.chromium.org/p/chromium/issues/attachment?aid=331957&signed_aid=yEqown9Qn32Do3_UyXfbGw==&inline=1
 - For non-PWAs:
   Use "Create shortcut?" instead of "Add to shelf" for the title.
   Use "Create" instead of "Add" for the button.
   Before: https://bugs.chromium.org/p/chromium/issues/attachment?aid=331945&signed_aid=vHvplIxwxZt1AbSCXNlRug==&inline=1
   After: https://bugs.chromium.org/p/chromium/issues/attachment?aid=331958&signed_aid=y82Q7ebdDf31vnnHy_vqcg==&inline=1

Bug: 789817, 822305
Change-Id: Ib2fbe35f43b575a985af6c50094235dc7693a149
Reviewed-on: https://chromium-review.googlesource.com/984916
Commit-Queue: Alan Cutter <alancutter@chromium.org>
Reviewed-by: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Reviewed-by: Ben Wells <benwells@chromium.org>
Cr-Commit-Position: refs/heads/master@{#546753}