Add support for shared texture and external BeginFrame in OSR mode (issue #1006)

- Add CefWindowInfo::shared_texture_enabled and
  CefRenderHandler::OnAcceleratedPaint for shared texture support. Currently
  only supported on Windows (D3D11).
- Add CefWindowInfo::external_begin_frame_enabled and
  CefBrowserHost::SendExternalBeginFrame for external begin frame support.

libcef_dll/ctocpp/render_handler_ctocpp.h

@@ -9,7 +9,7 @@
 // implementations. See the translator.README.txt file in the tools directory
 // for more information.
 //
-// $hash=46dd8560076264a776129a02ba11e2c2f56bf209$
+// $hash=2f19b04733f565830f873853695e9163086a8ee0$
 //
 
 #ifndef CEF_LIBCEF_DLL_CTOCPP_RENDER_HANDLER_CTOCPP_H_
@@ -52,6 +52,10 @@ class CefRenderHandlerCToCpp
                const void* buffer,
                int width,
                int height) override;
+  void OnAcceleratedPaint(CefRefPtr<CefBrowser> browser,
+                          PaintElementType type,
+                          const RectList& dirtyRects,
+                          void* shared_handle) override;
   void OnCursorChange(CefRefPtr<CefBrowser> browser,
                       CefCursorHandle cursor,
                       CursorType type,