For a while now, Chrome, on Windows in particular, has been getting a new set of menus, bigger and whiter than before.Google is doing this for the menus to work better with touch interfaces, but the vast, vast majority of people don't have touch input on their desktops and laptops and even those that do rarely use it.
And for them, the new menus are a step backwards. While they look a bit slicker and cleaner than the stock Windows menus, they're also significantly larger, sometime taking up huge portions of the screen for no good reason.
The good news is that, for now at least, you can disable the new style menus and revert back to the old ones.
It's not hard to do it either, you just have to launch Chrome with the --disable-new-menu-style flag either from the command line or from a shortcut.
On Windows, an easy way to do this is to right click on a Chrome shortcut, select properties and add the flag above in the target field after the path to Chrome, in the Shortcut tab.
As long as you launch Chrome from that shortcut, you'll get the old-style menus back. Don't get too excited though, Google is working on removing most platform specific code and this means UI code as well.
There are some bugs with the old menu style already, as you can see in the screenshot of Chrome 28. It may be that at some point in the future, only the Chrome-provided UI elements, including menus, will be supported.
Considering that Google already has to implement features such menus and other things that are normally taken care of by the OS, in Chrome OS, it makes sense to use that code on all the platforms where Chrome is available, within reason, to reduce the amount code Google has to write twice or three or four times over, for each platform.