Prefer external video codecs over internal in SDP

webrtc/media/engine/webrtcvideoengine_unittest.cc

Index: webrtc/media/engine/webrtcvideoengine_unittest.cc
diff --git a/webrtc/media/engine/webrtcvideoengine_unittest.cc b/webrtc/media/engine/webrtcvideoengine_unittest.cc
index 9d4c809f4de6bd6ae04eee2f1c320600b52e1ab1..51f6e9c656d748bd0b6246059a6219f2a61475a5 100644
--- a/webrtc/media/engine/webrtcvideoengine_unittest.cc
+++ b/webrtc/media/engine/webrtcvideoengine_unittest.cc
@@ -819,12 +819,12 @@ TEST_F(WebRtcVideoEngineTest, ReportSupportedExternalCodecs) {
 
   std::vector<cricket::VideoCodec> codecs(engine_.codecs());
   ASSERT_GE(codecs.size(), 2u);
-  cricket::VideoCodec internal_codec = codecs.front();
-  cricket::VideoCodec external_codec = codecs.back();
+  cricket::VideoCodec external_codec = codecs[0];
+  cricket::VideoCodec internal_codec = codecs[1];
 
-  // The external codec will appear last in the vector.
-  EXPECT_EQ("VP8", internal_codec.name);
+  // The external codec will appear first in the vector.
   EXPECT_EQ("FakeExternalCodec", external_codec.name);
+  EXPECT_EQ("VP8", internal_codec.name);
 }
 
 // Test that an external codec that was added after the engine was initialized
@@ -836,15 +836,15 @@ TEST_F(WebRtcVideoEngineTest, ReportSupportedExternalCodecsWithAddedCodec) {
   engine_.SetExternalEncoderFactory(&encoder_factory);
   engine_.Init();
 
-  // The first external codec will appear last in the vector.
+  // The first external codec will appear first in the vector.
   std::vector<cricket::VideoCodec> codecs_before(engine_.codecs());
-  EXPECT_EQ("FakeExternalCodec1", codecs_before.back().name);
+  EXPECT_EQ("FakeExternalCodec1", codecs_before.front().name);
 
   // Add second codec.
   encoder_factory.AddSupportedVideoCodecType("FakeExternalCodec2");
   std::vector<cricket::VideoCodec> codecs_after(engine_.codecs());
   EXPECT_EQ(codecs_before.size() + 1, codecs_after.size());
-  EXPECT_EQ("FakeExternalCodec2", codecs_after.back().name);
+  EXPECT_EQ("FakeExternalCodec2", codecs_after[1].name);
 }
 
 TEST_F(WebRtcVideoEngineTest, RegisterExternalDecodersIfSupported) {
@@ -1066,6 +1066,11 @@ class WebRtcVideoChannelTest : public WebRtcVideoEngineTest {
     ASSERT_TRUE(channel_->SetSendParameters(send_parameters_));
   }
 
+  void TearDown() override {
+    channel_ = nullptr;
+    fake_call_ = nullptr;
+  }
+
  protected:
   FakeVideoSendStream* AddSendStream() {
     return AddSendStream(StreamParams::CreateLegacy(++last_ssrc_));
@@ -1975,6 +1980,8 @@ class Vp9SettingsTest : public WebRtcVideoChannelTest {
     // Remove references to encoder_factory_ since this will be destroyed
     // before channel_ and engine_.
     ASSERT_TRUE(channel_->SetSendParameters(send_parameters_));
+
+    WebRtcVideoChannelTest::TearDown();
   }
 
   cricket::FakeWebRtcVideoEncoderFactory encoder_factory_;