Revert 221185 "Worked around bug with gtest filters on Linux."

The bug we were working around has been fixed, so we can safely revert this workaround.

BUG=285051

> Worked around bug with gtest filters on Linux.
> 
> We have temporarily disabled all WebRTC content_browsertests on Linux. This causes our custom build steps to hang because they no longer select any test cases on Linux, triggering bug 285051. This works around that bug so we don't have to disable the step and restart all our masters.
> 
> BUG=285051
> TBR=tommi@chromium.org
> NOTRY=True
> 
> Review URL: https://codereview.chromium.org/23513014

TBR=phoglund@chromium.org

Review URL: https://codereview.chromium.org/23601014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@221364 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/media/webrtc_browsertest.cc

@@ -48,13 +48,6 @@ namespace content {
 #if defined(OS_LINUX)
 // All tests are flaky on Linux: crbug.com/281492.
 #define MAYBE_WebrtcBrowserTest DISABLED_WebrtcBrowserTest
-
-// Workaround for crbug.com/285051. This can safely be removed if any of the
-// cases selected by --gtest_filter=WebRTC*:Webrtc*:*Dtmf get re-enabled.
-class WebrtcWorkaroundBugWithEmptyFilter: public ContentBrowserTest {};
-IN_PROC_BROWSER_TEST_F(WebrtcWorkaroundBugWithEmptyFilter, Succeeds) {
-  ASSERT_TRUE(true);
-}
 #else
 #define MAYBE_WebrtcBrowserTest WebrtcBrowserTest
 #endif