Switch from RTC_DISABLE_VP9 to RTC_ENABLE_VP9.

RTC_ENABLE_VP9 is more natural to deal with then RTC_DISABLE_VP9.
In all the places this macro is used, WebRTC needs to do more things
so it is easier to "do more if RTC_ENABLE_VP9 is defined" than
"do more if RTC_DISABLE_VP9 is not defined".

Bug: None
Change-Id: If992e5c554173e6af3f030f6e0fd21bd82acf9eb
No-Try: True
Reviewed-on: https://webrtc-review.googlesource.com/c/111242
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25679}
diff --git a/BUILD.gn b/BUILD.gn
index c67602c..5e0503d 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -223,8 +223,8 @@
     defines += [ "WEBRTC_INCLUDE_INTERNAL_AUDIO_DEVICE" ]
   }
 
-  if (!rtc_libvpx_build_vp9) {
-    defines += [ "RTC_DISABLE_VP9" ]
+  if (rtc_libvpx_build_vp9) {
+    defines += [ "RTC_ENABLE_VP9" ]
   }
 
   if (rtc_enable_sctp) {
diff --git a/api/video_codecs/test/builtin_video_encoder_factory_unittest.cc b/api/video_codecs/test/builtin_video_encoder_factory_unittest.cc
index 73957c9..30754d9 100644
--- a/api/video_codecs/test/builtin_video_encoder_factory_unittest.cc
+++ b/api/video_codecs/test/builtin_video_encoder_factory_unittest.cc
@@ -27,11 +27,11 @@
       break;
     }
   }
-#if defined(RTC_DISABLE_VP9)
-  EXPECT_FALSE(claims_vp9_support);
-#else
+#if defined(RTC_ENABLE_VP9)
   EXPECT_TRUE(claims_vp9_support);
-#endif  // defined(RTC_DISABLE_VP9)
+#else
+  EXPECT_FALSE(claims_vp9_support);
+#endif  // defined(RTC_ENABLE_VP9)
 }
 
 }  // namespace webrtc
diff --git a/media/engine/webrtcvideoengine_unittest.cc b/media/engine/webrtcvideoengine_unittest.cc
index cf16214..ab04fa6 100644
--- a/media/engine/webrtcvideoengine_unittest.cc
+++ b/media/engine/webrtcvideoengine_unittest.cc
@@ -554,7 +554,7 @@
       codecs, FindMatchingCodec(codecs, cricket::VideoCodec(h264_high))->id));
 }
 
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
 TEST_F(WebRtcVideoEngineTest, CanConstructDecoderForVp9EncoderFactory) {
   encoder_factory_->AddSupportedVideoCodecType("VP9");
 
@@ -564,7 +564,7 @@
   EXPECT_TRUE(
       channel->AddRecvStream(cricket::StreamParams::CreateLegacy(kSsrc)));
 }
-#endif  // !defined(RTC_DISABLE_VP9)
+#endif  // defined(RTC_ENABLE_VP9)
 
 TEST_F(WebRtcVideoEngineTest, PropagatesInputFrameTimestamp) {
   encoder_factory_->AddSupportedVideoCodecType("VP8");
diff --git a/modules/video_coding/codecs/test/videocodec_test_libvpx.cc b/modules/video_coding/codecs/test/videocodec_test_libvpx.cc
index 810d008..7208d39 100644
--- a/modules/video_coding/codecs/test/videocodec_test_libvpx.cc
+++ b/modules/video_coding/codecs/test/videocodec_test_libvpx.cc
@@ -90,7 +90,7 @@
 }
 }  // namespace
 
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
 TEST(VideoCodecTestLibvpx, HighBitrateVP9) {
   auto config = CreateConfig();
   config.SetCodecSettings(cricket::kVp9CodecName, 1, 1, 1, false, true, false,
@@ -200,7 +200,7 @@
 // TODO(marpan): Add temporal layer test for VP9, once changes are in
 // vp9 wrapper for this.
 
-#endif  // !defined(RTC_DISABLE_VP9)
+#endif  // defined(RTC_ENABLE_VP9)
 
 TEST(VideoCodecTestLibvpx, HighBitrateVP8) {
   auto config = CreateConfig();
diff --git a/modules/video_coding/codecs/vp9/vp9_noop.cc b/modules/video_coding/codecs/vp9/vp9_noop.cc
index b058c2d..8f9d71c 100644
--- a/modules/video_coding/codecs/vp9/vp9_noop.cc
+++ b/modules/video_coding/codecs/vp9/vp9_noop.cc
@@ -9,9 +9,9 @@
  *
  */
 
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
 #error
-#endif  // !defined(RTC_DISABLE_VP9)
+#endif  // defined(RTC_ENABLE_VP9)
 
 #include "modules/video_coding/codecs/vp9/include/vp9.h"
 
diff --git a/sdk/objc/components/video_codec/RTCDefaultVideoDecoderFactory.m b/sdk/objc/components/video_codec/RTCDefaultVideoDecoderFactory.m
index c7d08ca..bdb1851 100644
--- a/sdk/objc/components/video_codec/RTCDefaultVideoDecoderFactory.m
+++ b/sdk/objc/components/video_codec/RTCDefaultVideoDecoderFactory.m
@@ -15,7 +15,7 @@
 #import "api/video_codec/RTCVideoCodecConstants.h"
 #import "api/video_codec/RTCVideoDecoderVP8.h"
 #import "base/RTCVideoCodecInfo.h"
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
 #import "api/video_codec/RTCVideoDecoderVP9.h"
 #endif
 
@@ -26,7 +26,7 @@
     return [[RTCVideoDecoderH264 alloc] init];
   } else if ([info.name isEqualToString:kRTCVideoCodecVp8Name]) {
     return [RTCVideoDecoderVP8 vp8Decoder];
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
   } else if ([info.name isEqualToString:kRTCVideoCodecVp9Name]) {
     return [RTCVideoDecoderVP9 vp9Decoder];
 #endif
@@ -39,7 +39,7 @@
   return @[
     [[RTCVideoCodecInfo alloc] initWithName:kRTCVideoCodecH264Name],
     [[RTCVideoCodecInfo alloc] initWithName:kRTCVideoCodecVp8Name],
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
     [[RTCVideoCodecInfo alloc] initWithName:kRTCVideoCodecVp9Name],
 #endif
   ];
diff --git a/sdk/objc/components/video_codec/RTCDefaultVideoEncoderFactory.m b/sdk/objc/components/video_codec/RTCDefaultVideoEncoderFactory.m
index b01c074..b72296b 100644
--- a/sdk/objc/components/video_codec/RTCDefaultVideoEncoderFactory.m
+++ b/sdk/objc/components/video_codec/RTCDefaultVideoEncoderFactory.m
@@ -15,7 +15,7 @@
 #import "api/video_codec/RTCVideoCodecConstants.h"
 #import "api/video_codec/RTCVideoEncoderVP8.h"
 #import "base/RTCVideoCodecInfo.h"
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
 #import "api/video_codec/RTCVideoEncoderVP9.h"
 #endif
 
@@ -44,7 +44,7 @@
 
   RTCVideoCodecInfo *vp8Info = [[RTCVideoCodecInfo alloc] initWithName:kRTCVideoCodecVp8Name];
 
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
   RTCVideoCodecInfo *vp9Info = [[RTCVideoCodecInfo alloc] initWithName:kRTCVideoCodecVp9Name];
 #endif
 
@@ -52,7 +52,7 @@
     constrainedHighInfo,
     constrainedBaselineInfo,
     vp8Info,
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
     vp9Info,
 #endif
   ];
@@ -63,7 +63,7 @@
     return [[RTCVideoEncoderH264 alloc] initWithCodecInfo:info];
   } else if ([info.name isEqualToString:kRTCVideoCodecVp8Name]) {
     return [RTCVideoEncoderVP8 vp8Encoder];
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
   } else if ([info.name isEqualToString:kRTCVideoCodecVp9Name]) {
     return [RTCVideoEncoderVP9 vp9Encoder];
 #endif
diff --git a/video/end_to_end_tests/codec_tests.cc b/video/end_to_end_tests/codec_tests.cc
index 0fd0399..67ef611 100644
--- a/video/end_to_end_tests/codec_tests.cc
+++ b/video/end_to_end_tests/codec_tests.cc
@@ -118,7 +118,7 @@
   RunBaseTest(&test);
 }
 
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
 TEST_P(CodecEndToEndTest, SendsAndReceivesVP9) {
   test::FunctionVideoEncoderFactory encoder_factory(
       []() { return VP9Encoder::Create(); });
@@ -177,7 +177,7 @@
   RunBaseTest(&test);
 }
 
-#endif  // !defined(RTC_DISABLE_VP9)
+#endif  // defined(RTC_ENABLE_VP9)
 
 #if defined(WEBRTC_USE_H264)
 class EndToEndTestH264 : public test::CallTest,
diff --git a/video/full_stack_tests.cc b/video/full_stack_tests.cc
index 3f7eee5..9a8d252 100644
--- a/video/full_stack_tests.cc
+++ b/video/full_stack_tests.cc
@@ -109,7 +109,7 @@
   bool generic_descriptor_enabled_;
 };
 
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
 TEST(FullStackTest, ForemanCifWithoutPacketLossVp9) {
   auto fixture = CreateVideoQualityTestFixture();
   ParamsWithLogging foreman_cif;
@@ -190,7 +190,7 @@
   fixture->RunWithAnalyzer(generator);
 }
 
-#endif  // !defined(RTC_DISABLE_VP9)
+#endif  // defined(RTC_ENABLE_VP9)
 
 #if defined(WEBRTC_LINUX)
 // Crashes on the linux trusty perf bot: bugs.webrtc.org/9129.
@@ -660,7 +660,7 @@
   fixture->RunWithAnalyzer(conf_motion_hd);
 }
 
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
 TEST(FullStackTest, ConferenceMotionHd2000kbps100msLimitedQueueVP9) {
   auto fixture = CreateVideoQualityTestFixture();
   ParamsWithLogging conf_motion_hd;
@@ -828,7 +828,7 @@
     150000, 200000, false, "VP8", 3,
     2,      400000, false, false, false, "ConferenceMotion_1280_720_50"};
 
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
 TEST(FullStackTest, ScreenshareSlidesVP9_2SL) {
   auto fixture = CreateVideoQualityTestFixture();
   ParamsWithLogging screenshare;
@@ -969,7 +969,7 @@
 }
 #endif  // !defined(WEBRTC_MAC)
 
-#endif  // !defined(RTC_DISABLE_VP9)
+#endif  // defined(RTC_ENABLE_VP9)
 
 // Android bots can't handle FullHD, so disable the test.
 // TODO(bugs.webrtc.org/9220): Investigate source of flakiness on Mac.
diff --git a/video/video_send_stream_tests.cc b/video/video_send_stream_tests.cc
index 81eebf8..42ba6d4 100644
--- a/video/video_send_stream_tests.cc
+++ b/video/video_send_stream_tests.cc
@@ -654,7 +654,7 @@
   RunBaseTest(&test);
 }
 
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
 // Disabled as flaky, see https://crbug.com/webrtc/7285 for details.
 TEST_P(VideoSendStreamTest, DISABLED_DoesUtilizeUlpfecForVp9WithNackEnabled) {
   test::FunctionVideoEncoderFactory encoder_factory(
@@ -662,7 +662,7 @@
   UlpfecObserver test(false, true, true, true, "VP9", &encoder_factory);
   RunBaseTest(&test);
 }
-#endif  // !defined(RTC_DISABLE_VP9)
+#endif  // defined(RTC_ENABLE_VP9)
 
 TEST_P(VideoSendStreamTest, SupportsUlpfecWithMultithreadedH264) {
   test::FunctionVideoEncoderFactory encoder_factory([]() {
@@ -805,7 +805,7 @@
   RunBaseTest(&test);
 }
 
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
 TEST_P(VideoSendStreamTest, SupportsFlexfecVp9) {
   test::FunctionVideoEncoderFactory encoder_factory(
       []() { return VP9Encoder::Create(); });
@@ -819,7 +819,7 @@
   FlexfecObserver test(false, true, "VP9", &encoder_factory, 1);
   RunBaseTest(&test);
 }
-#endif  // defined(RTC_DISABLE_VP9)
+#endif  // defined(RTC_ENABLE_VP9)
 
 TEST_P(VideoSendStreamTest, SupportsFlexfecH264) {
   test::FunctionVideoEncoderFactory encoder_factory([]() {
@@ -3083,7 +3083,7 @@
   RunBaseTest(&test);
 }
 
-#if !defined(RTC_DISABLE_VP9)
+#if defined(RTC_ENABLE_VP9)
 class Vp9HeaderObserver : public test::SendTest {
  public:
   Vp9HeaderObserver()
@@ -3576,7 +3576,7 @@
 
   RunBaseTest(&test);
 }
-#endif  // !defined(RTC_DISABLE_VP9)
+#endif  // defined(RTC_ENABLE_VP9)
 
 void VideoSendStreamTest::TestRequestSourceRotateVideo(
     bool support_orientation_ext) {