[ScreenOrientation] Hide ScreenOrientationProvider inside WebContentsImpl.

content/public/browser/web_contents.h

Index: content/public/browser/web_contents.h
diff --git a/content/public/browser/web_contents.h b/content/public/browser/web_contents.h
index ffcb4b123ec75d027b41a7c68be882daba3ffd19..5a509ef831b9a4278909e212dd8b5ac1558e563b 100644
--- a/content/public/browser/web_contents.h
+++ b/content/public/browser/web_contents.h
@@ -21,6 +21,7 @@
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/page_navigator.h"
 #include "content/public/browser/save_page_type.h"
+#include "content/public/browser/screen_orientation_delegate.h"
 #include "content/public/browser/site_instance.h"
 #include "content/public/browser/web_ui.h"
 #include "content/public/common/stop_find_action.h"
@@ -191,6 +192,10 @@ class WebContents : public PageNavigator,
   CONTENT_EXPORT static WebContents* FromFrameTreeNodeId(
       int frame_tree_node_id);
 
+  // Sets delegate for platform specific screen orientation functionality.
+  CONTENT_EXPORT static void SetScreenOrientationDelegate(
+      ScreenOrientationDelegate* delegate);
+
   ~WebContents() override {}
 
   // Intrinsic tab state -------------------------------------------------------