views: Support configuration of initial window show state

Known issues:
- Exiting full-screen mode currently crashes with the Chrome runtime
  (see issue #3182).

include/internal/cef_types.h

@@ -1159,7 +1159,7 @@ typedef enum {
   // A resource that a plugin requested.
   ///
   RT_PLUGIN_RESOURCE,
-  
+
   ///
   // A main-frame service worker navigation preload request.
   ///
@@ -3219,6 +3219,16 @@ typedef enum {
   CEF_DOCKING_MODE_CUSTOM,
 } cef_docking_mode_t;
 
+///
+// Show states supported by CefWindowDelegate::GetInitialShowState.
+///
+typedef enum {
+  CEF_SHOW_STATE_NORMAL = 1,
+  CEF_SHOW_STATE_MINIMIZED,
+  CEF_SHOW_STATE_MAXIMIZED,
+  CEF_SHOW_STATE_FULLSCREEN,
+} cef_show_state_t;
+
 #ifdef __cplusplus
 }
 #endif