[omnibox] Added 'OmniboxTailSuggestions' flag

components/omnibox/browser/omnibox_field_trial.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/omnibox/browser/omnibox_field_trial.h"
 
 #include <cmath>
 #include <string>
 
 #include "base/command_line.h"
@@ skipping 24 matching lines @@
 // Finch experiment arm which sends an experiment ID to GWS which triggers
 // serving the new types.
 const base::Feature kNewOmniboxAnswerTypes{"NewOmniboxAnswerTypes",
                                            base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Feature used to enable the transmission of entity suggestions from GWS
 // to this client.
 const base::Feature kOmniboxEntitySuggestions{
     "OmniboxEntitySuggestions", base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Feature used to enable the transmission of tail suggestions from GWS
+// to this client.
+const base::Feature kOmniboxTailSuggestions{
+    "OmniboxTailSuggestions", base::FEATURE_DISABLED_BY_DEFAULT};

[Mark P, 2017/05/31 23:17:13]

Do you want an OS_ANDROID: enabled by default statement here?  Otherwise this
implies that it's disabled by default everywhere, which isn't the case.  (It
works on ANDROID already.)

Or revise the comment.

[Kevin Bailey, 2017/06/01 14:32:42]

I revised the comment, since all the flag does is enable a particular
experiment.

[Mark P, 2017/06/01 16:23:58]

Acknowledged.

+
 // Feature used to enable clipboard provider, which provides the user with
 // suggestions of the URL in the user's clipboard (if any) upon omnibox focus.
 const base::Feature kEnableClipboardProvider {
   "OmniboxEnableClipboardProvider",
 #if defined(OS_IOS)
       base::FEATURE_ENABLED_BY_DEFAULT
 #else
       base::FEATURE_DISABLED_BY_DEFAULT
 #endif
 };
@@ skipping 777 matching lines @@
   if (it != params.end())
     return it->second;
   // Fall back to the global instant extended context.
   it = params.find(rule + ":" + page_classification_str + ":*");
   if (it != params.end())
     return it->second;
   // Look up rule in the global context.
   it = params.find(rule + ":*:*");
   return (it != params.end()) ? it->second : std::string();
 }