Remove autoplay-muted-videos feature flag.

content/renderer/render_view_impl.cc

Index: content/renderer/render_view_impl.cc
diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index 14a3e97ea2d7698f053d971bfdde86b86d814da8..f07b6efa733b597a3db334aa7e89dcb7d7555999 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -1136,6 +1136,7 @@ void RenderView::ApplyWebPreferences(const WebPreferences& prefs,
       static_cast<WebSettings::ProgressBarCompletion>(
           prefs.progress_bar_completion));
   settings->setPreferHiddenVolumeControls(true);
+  settings->setSpellCheckEnabledByDefault(prefs.spellcheck_enabled_by_default);
 
   // Force preload=none and disable autoplay on older or low end Android
   // platforms because their media pipelines are not stable enough to handle
@@ -1144,10 +1145,8 @@ void RenderView::ApplyWebPreferences(const WebPreferences& prefs,
       base::android::BuildInfo::GetInstance()->sdk_int() <=
           base::android::SDK_VERSION_JELLY_BEAN_MR2 ||
       base::SysInfo::IsLowEndDevice();
+  // TODO(mlamouri): rename this setting "isLowEndDevice".
   settings->setForcePreloadNoneForMediaElements(is_low_end_device);
-  WebRuntimeFeatures::enableAutoplayMutedVideos(
-      prefs.autoplay_muted_videos_enabled && !is_low_end_device);

[mlamouri (slow - plz ping), 2016/11/04 16:18:54]

Note that autoplay muted is always enabled because there is a CL that uses the
"setForcePreloadNoneForMediaElements" signal to not autoplay in this case.

-  settings->setSpellCheckEnabledByDefault(prefs.spellcheck_enabled_by_default);
 #endif
 
   settings->setAutoplayExperimentMode(