Revert "linux_aura: Implement SetOpacity()."

This reverts r201447. SetOpacity() was hooked up backwards; I got confused
while reading the GTK+ code. However, if the "255 -" is simply removed, menus
stop showing. It looks like the menu system is still calling SetOpacity(0).

BUG=none
TBR=sidharthms@google.com,sky@chromium.org

Review URL: https://codereview.chromium.org/16189008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@202910 0039d316-1c4b-4281-b951-d872f2087c98

ui/views/widget/desktop_aura/desktop_root_window_host_x11.cc

@@ -74,7 +74,6 @@ const char* kAtomsToCache[] = {
   "_NET_WM_STATE_HIDDEN",
   "_NET_WM_STATE_MAXIMIZED_HORZ",
   "_NET_WM_STATE_MAXIMIZED_VERT",
-  "_NET_WM_WINDOW_OPACITY",
   "XdndActionAsk",
   "XdndActionCopy"
   "XdndActionLink",
@@ -638,20 +637,8 @@ bool DesktopRootWindowHostX11::IsFullscreen() const {
 }
 
 void DesktopRootWindowHostX11::SetOpacity(unsigned char opacity) {
-  // X server opacity is in terms of 32 bit unsigned int space, and counts from
-  // the opposite direction.
-  unsigned int cardinality = (255 - opacity) * 0x1010101;
-
-  if (cardinality == 0xffffffff) {
-    XDeleteProperty(xdisplay_, xwindow_,
-                    atom_cache_.GetAtom("_NET_WM_WINDOW_OPACITY"));
-  } else {
-    XChangeProperty(xdisplay_, xwindow_,
-                    atom_cache_.GetAtom("_NET_WM_WINDOW_OPACITY"),
-                    XA_CARDINAL, 32,
-                    PropModeReplace,
-                    reinterpret_cast<unsigned char*>(&cardinality), 1);
-  }
+  // TODO(erg):
+  NOTIMPLEMENTED();
 }
 
 void DesktopRootWindowHostX11::SetWindowIcons(