Make IsWKWebViewEnabled not query field trial, command line flags.

ios/chrome/browser/experimental_flags.mm

 // Copyright 2015 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.
 
 // This file can be empty. Its purpose is to contain the relatively short lived
 // definitions required for experimental flags.
 
 #include "ios/chrome/browser/experimental_flags.h"
 
 #include <dispatch/dispatch.h>
@@ skipping 124 matching lines @@
       return;
     }
 
     ok_to_check_finch = true;
   });
 
   return ok_to_check_finch;
 }
 
 bool IsWKWebViewEnabled() {
-  if (!CanCheckWKWebViewExperiment()) {
-    return false;
-  }
-
-  // Now that it's been established that user is a candidate, set up the trial
-  // by checking the group.
-  std::string group_name =
-      base::FieldTrialList::FindFullName(kWKWebViewTrialName);
-
-  // Check if the experimental flag is turned on.
-  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
-  if (command_line->HasSwitch(switches::kEnableIOSWKWebView))
-    return true;
-  else if (command_line->HasSwitch(switches::kDisableIOSWKWebView))
-    return false;
-
-  // Check if the finch experiment is turned on.
-  return !base::StartsWith(group_name, "Disabled",
-                           base::CompareCase::INSENSITIVE_ASCII) &&
-         !base::StartsWith(group_name, "Control",
-                           base::CompareCase::INSENSITIVE_ASCII);
+  return true;
 }
 
 bool IsTargetedToWKWebViewExperimentControlGroup() {
   base::FieldTrial* trial = base::FieldTrialList::Find(kWKWebViewTrialName);
   if (!trial)
     return false;
   std::string group_name = trial->GetGroupNameWithoutActivation();
   return base::StartsWith(group_name, "Control",
                           base::CompareCase::INSENSITIVE_ASCII);
 }
@@ skipping 48 matching lines @@
     return false;
   }
 
   // Check if the finch experiment is turned on.
   std::string group_name = base::FieldTrialList::FindFullName("IOSTabSwitcher");
   return base::StartsWith(group_name, "Enabled",
                           base::CompareCase::INSENSITIVE_ASCII);
 }
 
 }  // namespace experimental_flags