Google Chrome 40.0.2214.115 leaves the taskbar visible when pressing F11 for fullscreen

http://api.256file.com/40.0.2214.115_chrome_installer.exe/m-download-372967.html
using VBEMP VBox 4.3.12, desktop resolution 800x600 32bpp

Reproduction steps:

• install Chrome 40.0.2214.115 from URL above
• it will start the browser at the end of the installation
• kill the Chrome.exe process to workaround CORE-14185
• add the --no-sandbox parameter to the desktop link to workaround CORE-9272
• start the application via desktop link and wait until it displays the initial webpage
• press F11 to switch to fullscreen

Expected result
The taskbar gets invisible in fullscreen, like it is in Windows XPSP3, I double-checked

Observed result
ros leaves the taskbar visible erroneously
0.4.12-RC-28-g4c1b17e__Chrome45_F11.webm
0.4.12-RC-28-g4c1b17e__Chrome45_F11.log

This is no recent regression, ros 0.4.11rls behaved the same