Disable two media browser tests

TBR=hbos@chromium.org
NOTRY=true

Bug: 1001364
Change-Id: Idf5ae6d99e038d159794e0cf18f9261d6d464c70
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1833283Reviewed-by: Xida Chen <xidachen@chromium.org>
Commit-Queue: Xida Chen <xidachen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#701566}

content/browser/media/media_browsertest.cc

@@ -162,7 +162,8 @@ IN_PROC_BROWSER_TEST_P(MediaTest, VideoBearSilentTheora) {
 }
 #endif  // !defined(OS_ANDROID)
 
-IN_PROC_BROWSER_TEST_P(MediaTest, VideoBearWebm) {
+// crbug.com/1001364: disabled due to flakiness.
+IN_PROC_BROWSER_TEST_P(MediaTest, DISABLED_VideoBearWebm) {
   PlayVideo("bear.webm", GetParam());
 }
 
@@ -210,7 +211,8 @@ IN_PROC_BROWSER_TEST_P(MediaTest, VideoBearMovPcmS16be) {
   PlayVideo("bear_pcm_s16be.mov", GetParam());
 }
 
-IN_PROC_BROWSER_TEST_P(MediaTest, VideoBearMovPcmS24be) {
+// crbug.com/1001364: disabled due to flakiness.
+IN_PROC_BROWSER_TEST_P(MediaTest, DISABLED_VideoBearMovPcmS24be) {
   PlayVideo("bear_pcm_s24be.mov", GetParam());
 }