Revert "Disable audio output for media browser_tests on Linux"

This reverts commit d888e096.

Reason for revert: Issue may be fixed now, lets see!

Original change's description:
> Disable audio output for media browser_tests on Linux
> 
> Due to problems on some bots failing to start PulseAudio and causing
> Chrome startup to hang, disabling audio output for media browser tests
> on Linux to avoid the hang.
> 
> Bug: 986021,1023029,1026849,1035472,1049467
> Test: modified browser_tests pass locally
> Change-Id: I29a996ee627bc4a5b93e5b8d6227dd7801998d11
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2056760
> Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
> Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
> Commit-Queue: John Rummell <jrummell@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#741613}

TBR=dalecurtis@chromium.org,jrummell@chromium.org

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

Bug: 986021, 1023029, 1026849, 1035472, 1049467, 1054560
Change-Id: Iffb9f8299c86d9a1eccb59f3db0e5f16d09b207a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2151049Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: John Rummell <jrummell@chromium.org>
Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759407}

chrome/browser/media/media_browsertest.cc

@@ -30,11 +30,6 @@ void MediaBrowserTest::SetUpCommandLine(base::CommandLine* command_line) {
   command_line->AppendSwitchASCII(
       switches::kAutoplayPolicy,
       switches::autoplay::kNoUserGestureRequiredPolicy);
-#if defined(OS_LINUX)
-  // Due to problems with PulseAudio failing to start, use a fake audio
-  // stream. crbug.com/1047655#c70
-  command_line->AppendSwitch(switches::kDisableAudioOutput);
-#endif
 
   std::vector<base::Feature> enabled_features = {
 #if defined(OS_ANDROID)
@@ -46,6 +41,12 @@ void MediaBrowserTest::SetUpCommandLine(base::CommandLine* command_line) {
     // Disable fallback after decode error to avoid unexpected test pass on
     // the fallback path.
     media::kFallbackAfterDecodeError,
+
+#if defined(OS_LINUX)
+    // Disable out of process audio on Linux due to process spawn
+    // failures. http://crbug.com/986021
+    features::kAudioServiceOutOfProcess,
+#endif
   };
 
   scoped_feature_list_.InitWithFeatures(enabled_features, disabled_features);

content/browser/media/media_browsertest.cc

@@ -35,11 +35,6 @@ void MediaBrowserTest::SetUpCommandLine(base::CommandLine* command_line) {
       switches::kAutoplayPolicy,
       switches::autoplay::kNoUserGestureRequiredPolicy);
   command_line->AppendSwitch(switches::kExposeInternalsForTesting);
-#if defined(OS_LINUX)
-  // Due to problems with PulseAudio failing to start, use a fake audio
-  // stream. crbug.com/1047655#c70
-  command_line->AppendSwitch(switches::kDisableAudioOutput);
-#endif
 
   std::vector<base::Feature> enabled_features = {
 #if defined(OS_ANDROID)
@@ -51,6 +46,12 @@ void MediaBrowserTest::SetUpCommandLine(base::CommandLine* command_line) {
     // Disable fallback after decode error to avoid unexpected test pass on
     // the fallback path.
     media::kFallbackAfterDecodeError,
+
+#if defined(OS_LINUX)
+    // Disable out of process audio on Linux due to process spawn
+    // failures. http://crbug.com/986021
+    features::kAudioServiceOutOfProcess,
+#endif
   };
 
   scoped_feature_list_.InitWithFeatures(enabled_features, disabled_features);