* Output of `node_modules/.bin/electron --version`: 2.0.12
* Operating System (Platform and Version): macOS 10.14

**Expected Behavior**
When having a window in simple fullscreen and you change display metrics or change from 1 monitor to 2 the window should size according to the new dimensions.

**Actual behavior**
The window size does not change when display metrics change.

**To Reproduce**
* Run Fiddle: https://gist.github.com/bpasero/e4013ea83033a8c231f58f94c0df57c3
* Change display metrics or change monitor count

=> the window is wrongly sized now and needs a transition from normal back to fullscreen to recover.
shell/browser/native_window_mac.h
gfx::Rect GetBounds() override;
  bool IsNormal() override;
  gfx::Rect GetNormalBounds() override;
  void SetContentSizeConstraints(
      const extensions::SizeConstraints& size_constraints) override;
  void SetResizable(bool resizable) override;
  bool MoveAbove(const std::string& sourceId) override;
  void MoveTop() override;
  bool IsResizable() override;
  void SetMovable(bool movable) override;
  bool IsMovable() override;
  void SetMinimizable(bool minimizable) override;
  bool IsMinimizable() override;
  void SetMaximizable(bool maximizable) override;
  bool IsMaximizable() override;
  void SetFullScreenable(bool fullscreenable) override;
  bool IsFullScreenable() override;
  void SetClosable(bool closable) override;
  bool IsClosable() override;
  void SetAlwaysOnTop(ui::ZOrderLevel z_order,
                      const std::string& level,
                      int relativeLevel) override;
  ui::ZOrderLevel GetZOrderLevel() override;
  void Center() override;
  void Invalidate() override;
  void SetTitle(const std::string& title) override;
  std::string GetTitle() override;
  void FlashFrame(bool flash) override;
  void SetSkipTaskbar(bool skip) override;
  void SetExcludedFromShownWindowsMenu(bool excluded) override;