Disable AudioCodingModuleTest.TestPacketLossStereo for iOS.

It failed twice in succession after https://codereview.webrtc.org/2752233002.

TBR=ossu@webrtc.org
NOTRY=True
BUG=webrtc:7057

Review-Url: https://codereview.webrtc.org/2778983003
Cr-Commit-Position: refs/heads/master@{#17410}
diff --git a/webrtc/modules/audio_coding/test/Tester.cc b/webrtc/modules/audio_coding/test/Tester.cc
index b62c881..0d3f3f4 100644
--- a/webrtc/modules/audio_coding/test/Tester.cc
+++ b/webrtc/modules/audio_coding/test/Tester.cc
@@ -159,7 +159,12 @@
   Trace::ReturnTrace();
 }
 
-TEST(AudioCodingModuleTest, TestPacketLossStereo) {
+// Disabled on ios as flake, see https://crbug.com/webrtc/7057
+#if defined(WEBRTC_IOS)
+TEST(AudioCodingModuleTest, DISABLED_TestPacketLossStereo) {
+#else
+  TEST(AudioCodingModuleTest, TestPacketLossStereo) {
+#endif
   Trace::CreateTrace();
   Trace::SetTraceFile((webrtc::test::OutputPath() +
       "acm_packetloss_trace.txt").c_str());