Disabled WebRtcBrowserTest.* on all platforms.

Tests are flaky, especially on WinXP bots.

BUG=470013
TBR=tommi@chromium.org

Review URL: https://codereview.chromium.org/1033593002

Cr-Commit-Position: refs/heads/master@{#321948}

content/browser/media/webrtc_browsertest.cc

@@ -34,7 +34,8 @@ namespace content {
 // Renderer crashes under Android ASAN: https://crbug.com/408496.
 #define MAYBE_WebRtcBrowserTest DISABLED_WebRtcBrowserTest
 #else
-#define MAYBE_WebRtcBrowserTest WebRtcBrowserTest
+// Test is flaky on all platforms. http://crbug.com/470013.
+#define MAYBE_WebRtcBrowserTest DISABLED_WebRtcBrowserTest
 #endif
 
 class MAYBE_WebRtcBrowserTest : public WebRtcContentBrowserTest {