Implement basic toolbar with Material Design and loading progress.
Currently the toolbar only offers Save and Print functionality, but in other CLs Bookmarks, Zoom and Goto Page features will be implemented.
BUG=
110020
Committed:
https://crrev.com/c514ed05c61d422829594f3919041d0729fe6d7a
Cr-Commit-Position: refs/heads/master@{#312311}