Add a mechanism to force parameters of a group to a specific value.

chrome/common/chrome_switches.cc

 // Copyright (c) 2012 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 "chrome/common/chrome_switches.h"
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 
 namespace switches {
@@ skipping 613 matching lines @@
 // These two flags are added around the switches about:flags adds to the
 // command line. This is useful to see which switches were added by about:flags
 // on about:version. They don't have any effect.
 const char kFlagSwitchesBegin[]             = "flag-switches-begin";
 const char kFlagSwitchesEnd[]               = "flag-switches-end";
 
 // Forces application mode. This hides certain system UI elements and forces
 // the app to be installed if it hasn't been already.
 const char kForceAppMode[]                  = "force-app-mode";
 
+// This option can be used to force parameters of field trials when testing
+// changes locally. The argument is a list of key/value pairs prefixed by
+// Trial/Group pair. The following shows setting parameters to 2 experiments
+// where in the first, it forces "id" to be "foo" for the "Enabled" group of
+// the "EnhancedBookmarks" trial:
+// "EnhancedBookmarks.Enabled:id/foo,Experiment2.Group1:key1/value1"
+// Trial names, groups names, parameter names, and value should all be URL
+// escaped for all non-alphanumeric characters.
+const char kForceFieldTrialParams[] = "force-fieldtrial-params";
+
 // Displays the First Run experience when the browser is started, regardless of
 // whether or not it's actually the First Run (this overrides kNoFirstRun).
 const char kForceFirstRun[]                 = "force-first-run";
 
 // Forces additional Chrome Variation Ids that will be sent in X-Client-Data
 // header, specified as a 64-bit encoded list of numeric experiment ids. Ids
 // prefixed with the character "t" will be treated as Trigger Variation Ids.
 const char kForceVariationIds[]             = "force-variation-ids";
 
 // These flags show the man page on Linux. They are equivalent to each
@@ skipping 736 matching lines @@
 
 // -----------------------------------------------------------------------------
 // DO NOT ADD YOUR CRAP TO THE BOTTOM OF THIS FILE.
 //
 // You were going to just dump your switches here, weren't you? Instead, please
 // put them in alphabetical order above, or in order inside the appropriate
 // ifdef at the bottom. The order should match the header.
 // -----------------------------------------------------------------------------
 
 }  // namespace switches