Enable media learning smoothness data collection.

This CL enables media machine learning's smoothness experiment, to
collect accuracy information.  It does not affect MediaCapabilities
predictions; the goal is to see if the ML predictions are good
enough to switch MediaCapabilities over to it.

Change-Id: I066751abde8034f0f67b5a6ea17fe7da86f39892
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2020565
Auto-Submit: Frank Liberato <liberato@chromium.org>
Commit-Queue: Ted Meyer <tmathmeyer@chromium.org>
Reviewed-by: Ted Meyer <tmathmeyer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#735219}

media/base/media_switches.cc

@@ -610,12 +610,12 @@ const base::Feature kMediaLearningExperiment{"MediaLearningExperiment",
 // Enables the general purpose media machine learning framework. Adds reporting
 // only; does not change media behavior.
 const base::Feature kMediaLearningFramework{"MediaLearningFramework",
-                                            base::FEATURE_DISABLED_BY_DEFAULT};
+                                            base::FEATURE_ENABLED_BY_DEFAULT};
 
 // Enables the smoothness prediction experiment.  Requires
 // kMediaLearningFramework to be enabled also, else it does nothing.
 const base::Feature kMediaLearningSmoothnessExperiment{
-    "MediaLearningSmoothnessExperiment", base::FEATURE_DISABLED_BY_DEFAULT};
+    "MediaLearningSmoothnessExperiment", base::FEATURE_ENABLED_BY_DEFAULT};
 
 // Enable aggregate power measurement for media playback.
 const base::Feature kMediaPowerExperiment{"MediaPowerExperiment",