Hi DPI support function doesn't release DC

[JeffryBooher]

The function below doesn't release the drawing context it uses to get the Device Capabilities which could lead to instability -- Windows will allocate memory for new ones (unless you change the CEF Window class to use a shared DC).

Even though this is only called once per Window, each new Debugger Window, Popup window (PSDLens Cloud Login), or using Debug > New Brackets Window will create a new window and eventually Brackets will run out of handles.

UINT cef_window::GetDPIScalingX() const
{
    HDC dc = GetDC();
    float lpx = dc ? GetDeviceCaps(dc,LOGPIXELSX):DEFAULT_WINDOWS_DPI ;
    //scale factor as it would look in a default(96dpi) screen. the default will be always 96 logical DPI when scaling is applied in windows.
    //see. https://msdn.microsoft.com/en-us/library/ms701681(v=vs.85).aspx 
    return (lpx/DEFAULT_WINDOWS_DPI)*100; 
}

[peterflynn]

@JeffryBooher Good catch!

@abose Can you look into this for 1.3? (Looks like this code is yours)

Lowering priority to Medium though, since opening new windows is a fairly uncommon workflow in Brackets currently, making the impact of this likely to be rare in practice.

[abose]

Pull request submitted.
adobe/brackets-shell#508

[prafulVaishnav]

PR has been merged to shell.