gtk: Fix BrowserWindow::HasModalDialog.

atom/browser/native_window_gtk.cc

@@ -256,11 +256,6 @@ bool NativeWindowGtk::IsKiosk() {
   return IsFullscreen();
 }
 
-bool NativeWindowGtk::HasModalDialog() {
-  // FIXME(zcbenz): Implement me.
-  return false;
-}
-
 gfx::NativeWindow NativeWindowGtk::GetNativeWindow() {
   return window_;
 }

atom/browser/native_window_gtk.h

@@ -60,7 +60,6 @@ class NativeWindowGtk : public NativeWindow,
   virtual void FlashFrame(bool flash) OVERRIDE;
   virtual void SetKiosk(bool kiosk) OVERRIDE;
   virtual bool IsKiosk() OVERRIDE;
-  virtual bool HasModalDialog() OVERRIDE;
   virtual gfx::NativeWindow GetNativeWindow() OVERRIDE;
 
   // Set the native window menu.