Revert of Disabling failing tests in WebRtcApprtcBrowserTest (patchset #2...

Revert of Disabling failing tests in WebRtcApprtcBrowserTest (patchset #2 id:20001 of https://codereview.chromium.org/1016693002/)

Reason for revert:
We have landed an update to the AppRTC app in https://codereview.chromium.org/1023683002/ now, so these tests should now work.

Original issue's description:
> Disabling failing tests in WebRtcApprtcBrowserTest.
>
> These tests will be enabled again once the AppRTC app is working again which we expect will happen rather soon.
>
> TBR=phoglund
> BUG=467471
>
> Committed: https://crrev.com/15103a5ff0f262c85309d4b6af957d7c089aab3d
> Cr-Commit-Position: refs/heads/master@{#320883}

TBR=phoglund@chromium.org,henrika@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=467471

Review URL: https://codereview.chromium.org/1027673002

Cr-Commit-Position: refs/heads/master@{#321527}

chrome/browser/media/chrome_webrtc_apprtc_browsertest.cc

@@ -232,9 +232,7 @@ class WebRtcApprtcBrowserTest : public WebRtcTestBase {
   base::Process collider_server_;
 };
 
-// Disabling while the AppRTC application is being fixed.
-// See crbug.com/467471 for details.
-IN_PROC_BROWSER_TEST_F(WebRtcApprtcBrowserTest, DISABLED_MANUAL_WorksOnApprtc) {
+IN_PROC_BROWSER_TEST_F(WebRtcApprtcBrowserTest, MANUAL_WorksOnApprtc) {
   // Disabled on Win XP: http://code.google.com/p/webrtc/issues/detail?id=2703.
   if (OnWinXp())
     return;
@@ -265,9 +263,7 @@ IN_PROC_BROWSER_TEST_F(WebRtcApprtcBrowserTest, DISABLED_MANUAL_WorksOnApprtc) {
 }
 
 #if defined(OS_LINUX)
-// Disabling while the AppRTC application is being fixed.
-// See crbug.com/467471 for details.
-#define MAYBE_MANUAL_FirefoxApprtcInteropTest DISABLED_MANUAL_FirefoxApprtcInteropTest
+#define MAYBE_MANUAL_FirefoxApprtcInteropTest MANUAL_FirefoxApprtcInteropTest
 #else
 // Not implemented yet on Windows and Mac.
 #define MAYBE_MANUAL_FirefoxApprtcInteropTest DISABLED_MANUAL_FirefoxApprtcInteropTest