Revert of Remove ignored return code from modules.

webrtc/modules/video_render/video_render.h

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 35 matching lines @@
                                                   kRenderDefault);
 
     /*
      *   Destroy a video render module object
      *
      *   module  - object to destroy
      */
     static void DestroyVideoRender(VideoRender* module);
 
     int64_t TimeUntilNextProcess() override = 0;
-    void Process() override = 0;
+    int32_t Process() override = 0;
 
     /**************************************************************************
      *
      *   Window functions
      *
      ***************************************************************************/
 
     /*
      *   Get window for this renderer
      */
@@ skipping 192 matching lines @@
 
     /*
      * Set a timout image. The image is rendered if no videoframe has been delivered
      */
     virtual int32_t SetTimeoutImage(const uint32_t streamId,
                                     const VideoFrame& videoFrame,
                                     const uint32_t timeout) = 0;
 };
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_VIDEO_RENDER_VIDEO_RENDER_H_