Test field trial group with startswith rather than equals.

webrtc/system_wrappers/source/field_trial_default.cc

 // Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 //
 // Use of this source code is governed by a BSD-style license
 // that can be found in the LICENSE file in the root of the source
 // tree. An additional intellectual property rights grant can be found
 // in the file PATENTS.  All contributing project authors may
 // be found in the AUTHORS file in the root of the source tree.
 //
 
 #include "webrtc/system_wrappers/include/field_trial.h"
@@ skipping 35 matching lines @@
     std::string field_value(trials_string, field_name_end + 1,
         field_value_end - field_name_end - 1);
     next_item = field_value_end + 1;
 
     if (name == field_name)
       return field_value;
   }
   return std::string();
 }
 
+bool IsEnabled(const char* name) {
+  return FindFullName(name).find("Enabled") == 0;
+}
+
 // Optionally initialize field trial from a string.
 void InitFieldTrialsFromString(const char* trials_string) {
   trials_init_string = trials_string;
 }
 
 const char* GetFieldTrialString() {
   return trials_init_string;
 }
 
 }  // namespace field_trial
 }  // namespace webrtc