Allow browser tests to run with dynamic CLD data.

chrome/browser/translate/translate_browser_test_utils.h

+// Copyright 2014 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_BROWSER_TRANSLATE_TRANSLATE_BROWSER_TEST_UTILS_H_
+#define CHROME_BROWSER_TRANSLATE_TRANSLATE_BROWSER_TEST_UTILS_H_
+
+#include "base/macros.h"
+
+namespace test {
+
+// A utility class that sets up CLD dynamic data upon calling Init() and cleans
+// it up when destroyed.
+//
+// This class is intended to be instantiated within IN_PROC_BROWSER_TEST_F
+// test fixtures; it uses ASSERT macros for correctness, so that tests will
+// fail gracefully in error conditions. Sample use:
+//
+//   #include "chrome/browser/translate/translate_browser_test_utils.h"
+//
+//   IN_PROC_BROWSER_TEST_F(BrowserTest, PageLanguageDetection) {
+//     test::ScopedCLDDynamicDataHarness dynamic_data_scope;
+//     ASSERT_NO_FATAL_FAILURE(dynamic_data_scope.Init());
+//     // ... your code that depends on language detection goes here
+//   }
+//
+// If you have a lot of tests that need language translation features, you can
+// add an instance of the ScopedCLDDynamicDataHarness to your test class'
+// private member variables and add the call to Init() into your Setup method.
+//
+// NB: Test data lives under src/chrome/test/data/cld2_component
+class ScopedCLDDynamicDataHarness {
+ public:
+  // Constructs the object, but does nothing. Call Init() to prepare the
+  // harness, and enclose that call in ASSERT_NO_FATAL_FAILURE(...).
+  ScopedCLDDynamicDataHarness();
+
+  // Reverses the work done by the constructor: any files and/or directories
+  // that would be created by the constructor are immediately and irrevocably
+  // deleted.
+  // If dynamic data is not currently available for any reason, this method has
+  // no net effect on the runtime.
+  ~ScopedCLDDynamicDataHarness();
+
+  // Call this method, wrapping it in ASSERT_NO_FATAL_FAILURE, to initialize
+  // the harness and trigger test failure of initialization fails.
+  void Init();
+
+ private:
+  void ClearStandaloneDataFileState();
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedCLDDynamicDataHarness);
+};
+
+}  // namespace test
+
+#endif  // CHROME_BROWSER_TRANSLATE_TRANSLATE_BROWSER_TEST_UTILS_H_