Build fix for for Windows 'unreachable code' warning.
Build fix for for Windows 'unreachable code' warning.

On non-Android platforms we inserted an early return in
FrameView::scrollbarsDisabled(). This left the return statement below
unreachable.

TBR=enne@chromium.org
BUG=424102

Review URL: https://codereview.chromium.org/764663002

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@186068 bbb929c8-8fbe-4397-9dbb-9b2b20218538

primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs