Revert 245433 "Linux Aura: Added --use-system-title-bar flag."

DesktopScreenX11Test.GetWindowAtScreenPoint in views_unittests is faling on "Linux Aura Tests" after this change.
http://build.chromium.org/p/chromium.linux/builders/Linux%20Aura%20Tests/builds/701

> Linux Aura: Added --use-system-title-bar flag.
> 
> This flag makes browser windows use the system window dressing and title
> bar, instead of the custom frame. This is a Linux Aura equivalent of the
> "Use System Title Bar and Border" preference in Linux GTK. (Eventually,
> this part will be controlled by the same preference, rather than this
> flag.)
> 
> With this flag, browser windows use the native system window decoration,
> with our custom close/minimize/maximize buttons removed, and the tab
> strip being condensed vertically with square corners (like the maximized
> tab strip).  Popup browser windows (including V1 apps and the Developer
> Tools window) drop the blue custom frame altogether in favour of the
> native frame.
> 
> BUG=317859
> TEST=With --use-system-title-bar, open a browser window. Both maximized
> and restored windows should have a system native title bar, and the tab
> strip should be compacted into a single row (as when maximized).
> TEST=With --use-system-title-bar, open a hosted app window. It should
> have a system native title bar, with no second blue title bar.
> 
> Review URL: https://codereview.chromium.org/111723012

TBR=mgiuca@chromium.org

Review URL: https://codereview.chromium.org/139303014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245470 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245470