Move uniformity trials to its own file.

chrome/common/metrics/variations/uniformity_field_trials.h

Index: chrome/common/metrics/variations/uniformity_field_trials.h
diff --git a/chrome/common/metrics/variations/uniformity_field_trials.h b/chrome/common/metrics/variations/uniformity_field_trials.h
new file mode 100644
index 0000000000000000000000000000000000000000..20c152e7499413476d43bdce27d2d2cb612574ae
--- /dev/null
+++ b/chrome/common/metrics/variations/uniformity_field_trials.h
@@ -0,0 +1,19 @@
+// Copyright (c) 2013 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.
+
+#ifndef CHROME_COMMON_METRICS_VARIATIONS_UNIFORMITY_FIELD_TRIALS_H_
+#define CHROME_COMMON_METRICS_VARIATIONS_UNIFORMITY_FIELD_TRIALS_H_
+
+#include "base/time.h"

[tfarina, 2013/03/05 03:30:38]

I think you could have forward declare this, 

+
+namespace chrome_variations {
+
+// A collection of one-time-randomized and session-randomized field trials
+// intended to test the uniformity and correctness of the field trial control,
+// bucketing and reporting systems.
+void SetupUniformityFieldTrials(const base::Time& install_date);

[tfarina, 2013/03/05 03:30:38]

and passed by value, since Time just holds a int64 type.

+
+}  // namespace chrome_variations
+
+#endif  // CHROME_COMMON_METRICS_VARIATIONS_UNIFORMITY_FIELD_TRIALS_H_