Unlaunch the HIDDEN mode.

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index 5fedf0348442c88ae90d52ead38f3cf97e100c94..1ffb482d1e82cc6c202e6ec2fc2c56de2248abbe 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -779,8 +779,6 @@ const char kIncognito[]                     = "incognito";
 // Controls the Instant field trial. Valid values are defined below. If an
 // unknown value is supplied on the command line, the field trial is disabled.
 const char kInstantFieldTrial[]             = "instant-field-trial";
-// The field trial is forced into the CONTROL group.
-const char kInstantFieldTrialControl[]      = "control";
 // The field trial is forced into the HIDDEN group.
 const char kInstantFieldTrialHidden[]       = "hidden";
 // The field trial is forced into the INSTANT group.
@@ -978,11 +976,6 @@ const char kPpapiFlashFieldTrialEnableByDefault[] = "enable-by-default";
 // renderer process rather than in a separate plugin process.
 const char kPpapiFlashInProcess[]           = "ppapi-flash-in-process";
 
-// Aggressively preloads the default search engine's Instant URL, so it's ready
-// to receive queries. Only has an effect if Instant is turned on (via "Enable
-// Instant for faster searching and browsing" in Preferences -> Basics).
-const char kPreloadInstantSearch[]          = "preload-instant-search";
-
 // Triggers prerendering of pages from suggestions in the omnibox. Only has an
 // effect when Instant is either disabled or restricted to search, and when
 // prerender is enabled.