Rebuild test history databases when starting up performance_ui_tests.

chrome/test/perf/generate_profile.h

+// 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_TEST_PERF_GENERATE_PROFILE_H_
+#define CHROME_TEST_PERF_GENERATE_PROFILE_H_
+
+namespace base {
+class FilePath;
+}
+
+// Addition types data can be generated for. By default only urls/visits are
+// added.
+enum GenerateProfileTypes {
+  TOP_SITES = 1 << 0,
+  FULL_TEXT = 1 << 1
+};
+
+// Generates a user profile and history by randomly generating data and feeding

[Randy Smith (Not in Mondays), 2013/04/29 18:49:13]

I'm made nervous by the word "randomly" in here--are you confident that the
random variation in data won't induce a random variation in loading time?  If
not, can we make it non-random data (i.e. the same data will be generated each
time)?

+// it to the history service. Returns true if successful.
+bool GenerateProfile(GenerateProfileTypes types,
+                     int urlcount,
+                     const base::FilePath& dst_dir);

[Paweł Hajdan Jr., 2013/04/26 23:19:32]

nit: Add WARN_UNUSED_RESULT from base/compiler_specific.h .

+
+#endif  // CHROME_TEST_PERF_GENERATE_PROFILE_H_