How to get the current URL from Chrome 28 from another Windows application?

Chrome supports the Windows accessibility APIs, so you can use those to extract information both from the chrome - including the broswer bar - and also from web pages. Think of this API as a more abstract version of enumerating window controls.

Check out the Inspect Objects tool to explore what information you can get access to - it does look as though the address bar and contents are available.

You can get the same information in C# using the AutomationElement set of classes:

• use AutomationElement windowEl = AutomationElement.FromHandle(new IntPtr(hwnd)); as a starting point if you know the HWND of the tree
• then try AutomationElement editEl = AutomationElement.FindFirst(TreeScope.Descendants, new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Edit)) to find the first element that has ControlType of Edit. FindFirst does a depth-first search of the tree, which looks like it will work in this case; can use the TreeWalker classes if you want to walk step-by-step yourself.
• 'cast' the found element to a ValuePattern using: ValuePattern vp = (ValuePattern) editEl.GetCurrentPattern(ValuePattern.Pattern);
• Finally, use string str = vp.Current.Value; to get the value of the edit.

AFAIK you could do this by creating a chrome extension which then communicates with the application using WebSockets.

There's even a Delphi implementation of the Web Socket protocol(with examples) -> DelphiWs

More relevant info here.That should get you started.