**Is your feature request related to a problem? Please describe.**
In windows tablet mode, you may want to change your UI. There is apps that enlarge the title bar or hide the title bar buttons since they are useless (in tablet mode, every window is forced into fullscreen mode and minimizing is disabled). The is no way to detect tablet mode in electron.

**Describe the solution you'd like**
~~Something like systemPreferences.tabletMode() and a `tablet-mode-changed` should be available~~
We need a BrowserWindow instance method like `window.getUserInteractionMode()` that gives us the primary input mode for a view. `window.resize` event should be sufficient to listen to changes to tablet mode. Here is more info: https://blogs.msdn.microsoft.com/oldnewthing/20160706-00/?p=93815

**Describe alternatives you've considered**
I looked into going to the Browser API  in renderer, but there is no clear way to check if a device is in tablet mode. You can basically just check if there is touch available, which is not the same.

**Additional context**
This is outlook hiding their title bar buttons in tablet mode.
<img width="850" alt="anmerkung" src="https://user-images.githubusercontent.com/4349324/46936928-42be3680-d060-11e8-8dfc-815ccac98e62.png">
<img width="849" alt="anmerkung2" src="https://user-images.githubusercontent.com/4349324/46936929-4356cd00-d060-11e8-8405-df5933e7cfbc.png">


shell/browser/native_window.h
virtual void SetExcludedFromShownWindowsMenu(bool excluded) = 0;
  virtual bool IsExcludedFromShownWindowsMenu() = 0;
  virtual void SetSimpleFullScreen(bool simple_fullscreen) = 0;
  virtual bool IsSimpleFullScreen() = 0;
  virtual void SetKiosk(bool kiosk) = 0;
  virtual bool IsKiosk() = 0;
  virtual void SetBackgroundColor(SkColor color) = 0;
  virtual SkColor GetBackgroundColor() = 0;
  virtual void SetHasShadow(bool has_shadow) = 0;
  virtual bool HasShadow() = 0;
  virtual void SetOpacity(const double opacity) = 0;
  virtual double GetOpacity() = 0;
  virtual void SetRepresentedFilename(const std::string& filename);
  virtual std::string GetRepresentedFilename();
  virtual void SetDocumentEdited(bool edited);
  virtual bool IsDocumentEdited();
  virtual void SetIgnoreMouseEvents(bool ignore, bool forward) = 0;
  virtual void SetContentProtection(bool enable) = 0;
  virtual void SetFocusable(bool focusable);
  virtual void SetMenu(ElectronMenuModel* menu);
  virtual void SetParentWindow(NativeWindow* parent);
  virtual void AddBrowserView(NativeBrowserView* browser_view) = 0;
  virtual void RemoveBrowserView(NativeBrowserView* browser_view) = 0;
  virtual content::DesktopMediaID GetDesktopMediaID() const = 0;
  virtual gfx::NativeView GetNativeView() const = 0;
  virtual gfx::NativeWindow GetNativeWindow() const = 0;
  virtual gfx::AcceleratedWidget GetAcceleratedWidget() const = 0;
  virtual NativeWindowHandle GetNativeWindowHandle() const = 0;
  
  enum class ProgressState {