Disable flaky WebRTC tests.

chrome/browser/media/webrtc/webrtc_video_quality_browsertest.cc

Index: chrome/browser/media/webrtc/webrtc_video_quality_browsertest.cc
diff --git a/chrome/browser/media/webrtc/webrtc_video_quality_browsertest.cc b/chrome/browser/media/webrtc/webrtc_video_quality_browsertest.cc
index 6d9a4aa967b99bdb6f74502becb9c5a1bbeed4bf..36de84b60fe51b79e49415ea892d7fddf9a8e3a5 100644
--- a/chrome/browser/media/webrtc/webrtc_video_quality_browsertest.cc
+++ b/chrome/browser/media/webrtc/webrtc_video_quality_browsertest.cc
@@ -342,20 +342,31 @@ INSTANTIATE_TEST_CASE_P(
     WebRtcVideoQualityBrowserTest,
     testing::ValuesIn(kVideoConfigurations));
 
+// Video quality tests are flaky on Windows. See http://crbug.com/webrtc/6484.
+#if defined(OS_WIN)
+#define MAYBE_TestVideoQualityVp8 DISABLED_TestVideoQualityVp8
+#define MAYBE_TestVideoQualityVp9 DISABLED_TestVideoQualityVp9
+#define MAYBE_TestVideoQualityH264 DISABLED_TestVideoQualityH264
+#else
+#define MAYBE_TestVideoQualityVp8 MANUAL_TestVideoQualityVp8
+#define MAYBE_TestVideoQualityVp9 MANUAL_TestVideoQualityVp9
+#define MAYBE_TestVideoQualityH264 MANUAL_TestVideoQualityH264
+#endif
+
 IN_PROC_BROWSER_TEST_P(WebRtcVideoQualityBrowserTest,
-                       MANUAL_TestVideoQualityVp8) {
+                       MAYBE_TestVideoQualityVp8) {
   TestVideoQuality("VP8");
 }
 
 IN_PROC_BROWSER_TEST_P(WebRtcVideoQualityBrowserTest,
-                       MANUAL_TestVideoQualityVp9) {
+                       MAYBE_TestVideoQualityVp9) {
   TestVideoQuality("VP9");
 }
 
 #if BUILDFLAG(RTC_USE_H264)
 
 IN_PROC_BROWSER_TEST_P(WebRtcVideoQualityBrowserTest,
-                       MANUAL_TestVideoQualityH264) {
+                       MAYBE_TestVideoQualityH264) {
   // Only run test if run-time feature corresponding to |rtc_use_h264| is on.
   if (!base::FeatureList::IsEnabled(content::kWebRtcH264WithOpenH264FFmpeg)) {
     LOG(WARNING) << "Run-time feature WebRTC-H264WithOpenH264FFmpeg disabled. "