Allow backgrounding processes on Mac

content/public/common/content_features.h

Index: content/public/common/content_features.h
diff --git a/content/public/common/content_features.h b/content/public/common/content_features.h
index 5dcb61e63e7c4fab96c0840f61dd786702095e0c..5b832066f452e29480bc96e63c9948f4e96412ce 100644
--- a/content/public/common/content_features.h
+++ b/content/public/common/content_features.h
@@ -71,6 +71,10 @@ CONTENT_EXPORT extern const base::Feature kWebPayments;
 CONTENT_EXPORT extern const base::Feature kWinSboxDisableExtensionPoints;
 #endif  // defined(OS_WIN)
 
+#if defined(OS_MACOSX)
+CONTENT_EXPORT extern const base::Feature kMacBackgroundInactiveTabs;

[shrike, 2016/10/31 17:26:05]

Technically the renderers are hidden. I think it's better to call this
kMacBackgroundHiddenRenderers so that the feature name is as clear as can be
(when you switch to another tab, is the old tab really inactive? Yes and no,
because it still might be doing some work).

[lgrey, 2016/10/31 19:22:02]

Done.

+#endif
+
 // DON'T ADD RANDOM STUFF HERE. Put it in the main section above in
 // alphabetical order, or in one of the ifdefs (also in order in each section).