+ Use sentence case for buttons
+ Chanage filled button side padding to 24dp
+ Change text button side padding to 8dp
+ Change clear browsing data setting button to filled button

Bug: 900760
Change-Id: Id9c01960464319c5b3ad974564b4637c8d9d0217
Reviewed-on: https://chromium-review.googlesource.com/c/1315214
Commit-Queue: Becky Zhou <huayinz@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606091}