Reland "Disable WebRtcBrowserTest.NegotiateNonCryptoCall on Mac"

This reverts commit b909c213.

Reason for revert: Re-Disable the flaky test until a fix is found

Original change's description:
> Revert "Disable WebRtcBrowserTest.NegotiateNonCryptoCall on Mac"
> 
> This reverts commit cfec3da6.
> 
> Reason for revert: Checking if flakiness is still happening on Mac ASAN bot
> 
> Original change's description:
> > Disable WebRtcBrowserTest.NegotiateNonCryptoCall on Mac
> >
> > TBR=chfremer@chromium.org
> >
> > Bug: 810321
> > Change-Id: Ia12ba855ab9fb8e66c9d48c8e66cf91f76f72e08
> > Reviewed-on: https://chromium-review.googlesource.com/908461
> > Reviewed-by: Olga Sharonova <olka@chromium.org>
> > Commit-Queue: Olga Sharonova <olka@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#535381}
> 
> TBR=olka@chromium.org,chfremer@chromium.org
> 
> # Not skipping CQ checks because original CL landed > 1 day ago.
> 
> Bug: 810321
> Change-Id: I6e021bca934428cf9c94a34d4f0e874c25868033
> Reviewed-on: https://chromium-review.googlesource.com/1010842
> Commit-Queue: Christian Fremerey <chfremer@chromium.org>
> Reviewed-by: Christian Fremerey <chfremer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#550380}

TBR=olka@chromium.org,chfremer@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 810321
Change-Id: I68a7e09599e1511e8b4c547e7932e874689ab224
Reviewed-on: https://chromium-review.googlesource.com/1013018Reviewed-by: Christian Fremerey <chfremer@chromium.org>
Commit-Queue: Christian Fremerey <chfremer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#550867}

content/browser/webrtc/webrtc_browsertest.cc

@@ -177,7 +177,13 @@ IN_PROC_BROWSER_TEST_F(MAYBE_WebRtcBrowserTest,
 
 // This test will modify the SDP offer to use no encryption, which should
 // cause SetLocalDescription to fail.
-IN_PROC_BROWSER_TEST_F(MAYBE_WebRtcBrowserTest, NegotiateNonCryptoCall) {
+// Flaky on MAC: http://crbug/810321.
+#if defined(OS_MACOSX)
+#define MAYBE_NegotiateNonCryptoCall DISABLED_NegotiateNonCryptoCall
+#else
+#define MAYBE_NegotiateNonCryptoCall NegotiateNonCryptoCall
+#endif
+IN_PROC_BROWSER_TEST_F(MAYBE_WebRtcBrowserTest, MAYBE_NegotiateNonCryptoCall) {
   MakeTypicalPeerConnectionCall("negotiateNonCryptoCall();");
 }