Profile Chooser: Show ink drop highlight when buttons are focused.

r515443 swapped out the custom higlighting in the Profile Chooser for ink drops
instead. However, this introduced a regression where the buttons would no longer
highlight on focus. Fix by turning on highlight on focus mode for ink drops.

Bug: 784235
Change-Id: Ib45cbbc82644279496bbab42e97406de96b4db7c
Reviewed-on: https://chromium-review.googlesource.com/765612
Commit-Queue: Trent Apted <tapted@chromium.org>
Reviewed-by: Trent Apted <tapted@chromium.org>
Cr-Commit-Position: refs/heads/master@{#515900}

chrome/browser/ui/views/hover_button.cc

@@ -41,8 +41,9 @@ HoverButton::HoverButton(views::ButtonListener* button_listener,
       DISTANCE_CONTROL_LIST_VERTICAL);
   SetBorder(CreateBorderWithVerticalSpacing(vert_spacing));
 
-  // Turn on highlighting when the button is hovered.
+  // Turn on highlighting when the button is hovered or focused.
   SetInkDropMode(views::InkDropHostView::InkDropMode::ON);
+  GetInkDrop()->SetShowHighlightOnFocus(true);
 }
 
 HoverButton::HoverButton(views::ButtonListener* button_listener,