Revert of Handle RenderProcessHostImpl::SetBackgrounded on Windows

base/process/process_win.cc

Index: base/process/process_win.cc
diff --git a/base/process/process_win.cc b/base/process/process_win.cc
index 8e5360b385603bd64cecf02e663123329a84381d..4e600f944db2063a6e97c0bd94c683a6e92471fd 100644
--- a/base/process/process_win.cc
+++ b/base/process/process_win.cc
@@ -6,7 +6,6 @@
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/metrics/field_trial.h"
 #include "base/process/kill.h"
 #include "base/win/windows_version.h"
 
@@ -166,21 +165,7 @@
     priority = value ? PROCESS_MODE_BACKGROUND_BEGIN :
                        PROCESS_MODE_BACKGROUND_END;
   } else {
-    // Experiment (http://crbug.com/458594) with using IDLE_PRIORITY_CLASS as a
-    // background priority for background renderers (this code path is
-    // technically for more than just the renderers but they're the only use
-    // case in practice and experimenting here direclty is thus easier -- plus
-    // it doesn't really hurt as above we already state our intent of using
-    // PROCESS_MODE_BACKGROUND_BEGIN if available which is essentially
-    // IDLE_PRIORITY_CLASS plus lowered IO priority). Enabled by default in the
-    // asbence of field trials to get coverage on the perf waterfall.
-    DWORD background_priority = IDLE_PRIORITY_CLASS;
-    base::FieldTrial* trial =
-        base::FieldTrialList::Find("BackgroundRendererProcesses");
-    if (trial && trial->group_name() == "AllowBelowNormalFromBrowser")
-      background_priority = BELOW_NORMAL_PRIORITY_CLASS;
-
-    priority = value ? background_priority : NORMAL_PRIORITY_CLASS;
+    priority = value ? BELOW_NORMAL_PRIORITY_CLASS : NORMAL_PRIORITY_CLASS;
   }
 
   return (::SetPriorityClass(Handle(), priority) != 0);