Ability to disable the effects of |rtc_use_h264| with DisableRtcUseH264.

webrtc/modules/video_coding/codecs/h264/h264.cc

 /*
  *  Copyright (c) 2015 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.
  *
  */
 
 #include "webrtc/modules/video_coding/codecs/h264/include/h264.h"
 
-#if defined(WEBRTC_THIRD_PARTY_H264)
+#if defined(WEBRTC_USE_H264)
+#include "webrtc/modules/video_coding/codecs/h264/h264_decoder_impl.h"
 #include "webrtc/modules/video_coding/codecs/h264/h264_encoder_impl.h"
-#include "webrtc/modules/video_coding/codecs/h264/h264_decoder_impl.h"
 #endif
 #if defined(WEBRTC_IOS)
 #include "webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_decoder.h"
 #include "webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_encoder.h"
 #endif
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/logging.h"
 
 namespace webrtc {
 
+namespace {
+
+#if defined(WEBRTC_USE_H264)
+bool g_rtc_use_h264 = true;
+#endif
+
+}  // namespace
+
+void DisableRtcUseH264() {
+#if defined(WEBRTC_USE_H264)
+  g_rtc_use_h264 = false;
+#endif
+}
+
 // We need this file to be C++ only so it will compile properly for all
 // platforms. In order to write ObjC specific implementations we use private
 // externs. This function is defined in h264.mm.
 #if defined(WEBRTC_IOS)
 extern bool IsH264CodecSupportedObjC();
 #endif
 
 // If any H.264 codec is supported (iOS HW or OpenH264/FFmpeg).
 bool IsH264CodecSupported() {
 #if defined(WEBRTC_IOS)
   if (IsH264CodecSupportedObjC()) {
     return true;
   }
 #endif
-#if defined(WEBRTC_THIRD_PARTY_H264)
-  return true;
+#if defined(WEBRTC_USE_H264)
+  return g_rtc_use_h264;
 #else
   return false;
 #endif
 }
 
 H264Encoder* H264Encoder::Create() {
   RTC_DCHECK(H264Encoder::IsSupported());
 #if defined(WEBRTC_IOS) && defined(WEBRTC_VIDEO_TOOLBOX_SUPPORTED)
   if (IsH264CodecSupportedObjC()) {
     LOG(LS_INFO) << "Creating H264VideoToolboxEncoder.";
     return new H264VideoToolboxEncoder();
   }
 #endif
-#if defined(WEBRTC_THIRD_PARTY_H264)
+#if defined(WEBRTC_USE_H264)
+  RTC_CHECK(g_rtc_use_h264);
   LOG(LS_INFO) << "Creating H264EncoderImpl.";
   return new H264EncoderImpl();
 #else
   RTC_NOTREACHED();
   return nullptr;
 #endif
 }
 
 bool H264Encoder::IsSupported() {
   return IsH264CodecSupported();
 }
 
 H264Decoder* H264Decoder::Create() {
   RTC_DCHECK(H264Decoder::IsSupported());
 #if defined(WEBRTC_IOS) && defined(WEBRTC_VIDEO_TOOLBOX_SUPPORTED)
   if (IsH264CodecSupportedObjC()) {
     LOG(LS_INFO) << "Creating H264VideoToolboxDecoder.";
     return new H264VideoToolboxDecoder();
   }
 #endif
-#if defined(WEBRTC_THIRD_PARTY_H264)
+#if defined(WEBRTC_USE_H264)
+  RTC_CHECK(g_rtc_use_h264);
   LOG(LS_INFO) << "Creating H264DecoderImpl.";
   return new H264DecoderImpl();
 #else
   RTC_NOTREACHED();
   return nullptr;
 #endif
 }
 
 bool H264Decoder::IsSupported() {
   return IsH264CodecSupported();
 }
 
 }  // namespace webrtc