Enable nacl_helper by default.

content/common/content_switches.cc

Index: content/common/content_switches.cc
diff --git a/content/common/content_switches.cc b/content/common/content_switches.cc
index 3df8a440d3b098957c6388bcac97a6b74fb5496d..511620afc48df0dbd059f474d8cca057c71ef79b 100644
--- a/content/common/content_switches.cc
+++ b/content/common/content_switches.cc
@@ -281,10 +281,6 @@ const char kLowLatencyAudio[]               = "enable-low-latency-audio";
 // (used for launching NaCl loader processes on 64-bit Windows).
 const char kNaClBrokerProcess[]             = "nacl-broker";
 
-// Enables experimental lightweight Native Client launcher for Linux
-// Value is the path to the helper binary.
-const char kNaClLinuxHelper[]               = "nacl-linux-helper";
-
 // Causes the process to run as a NativeClient loader.
 const char kNaClLoaderProcess[]             = "nacl-loader";