DevTools: Add a power icon for power overview.

See https://codereview.chromium.org/234713002/

BUG=337138

Review URL: https://codereview.chromium.org/235863022

git-svn-id: svn://svn.chromium.org/blink/trunk@171844 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Oilpan: fix build after r171843.

R=
BUG=357586
NOTRY=true

Review URL: https://codereview.chromium.org/240503006

git-svn-id: svn://svn.chromium.org/blink/trunk@171845 bbb929c8-8fbe-4397-9dbb-9b2b20218538