Improve tablet mode detection on Windows 10+

This patch introduces the following:-
1. A function IsWindows10TabletMode which uses the new WRL API's on Windows 10 to query the current interaction mode.
   As per msdn these API's can be called from Win32 apps.
   https://msdn.microsoft.com/en-us/library/windows/hardware/dn917883(v=vs.85).aspx
   https://software.intel.com/en-us/articles/detecting-slateclamshell-mode-screen-orientation-in-convertible-pc
   These API's however appear to always return UserModeTouch which indicates tablet mode on the Surface 4 configuration
   I was testing with.

2. If the IsTabletDevice function returns true we don't attempt to detect keyboards and just assume that there is
   no keyboard attached.

BUG=497381

Review URL: https://codereview.chromium.org/1783123003

Cr-Commit-Position: refs/heads/master@{#380864}
1 file changed