Show --enable-pnacl in about:flags.

chrome/app/generated_resources.grd

Index: chrome/app/generated_resources.grd
diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index 86f666f94e99e464b938476ab5102046c25cfd5c..4d215764ea12eb2ccc962959d87fed61bee7f2c4 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -5297,6 +5297,12 @@ Keep your key file in a safe place. You will need it to create new versions of y
       <message name="IDS_FLAGS_NACL_GDB_SCRIPT_DESCRIPTION" desc="Description of the 'Script executed by Native Client application debugger at startup' lab.">
         Set path to script with gdb commands which will be executed by nacl-gdb at startup.
       </message>
+      <message name="IDS_FLAGS_ENABLE_PNACL_NAME" desc="Name of the 'Enable Portable Native Client' lab.">
+        Portable Native Client.
+      </message>
+      <message name="IDS_FLAGS_ENABLE_PNACL_DESCRIPTION" desc="Description of the 'Enable Portable Native Client' lab.">
+        Enable support for Portable Native Client.
+      </message>
       <message name="IDS_FLAGS_DOWNLOADS_NEW_UI_NAME" desc="Name of the 'New Downloads UI' lab.">
         New Downloads UI
       </message>