Refactor language detection logic to allow non-static CLD data sources.

chrome/browser/translate/cld_data_harness_factory.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_CLD_DATA_HARNESS_FACTORY_H_
+#define CHROME_BROWSER_TRANSLATE_CLD_DATA_HARNESS_FACTORY_H_
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/browser/translate/cld_data_harness.h"
+
+namespace test {
+
+// Testing class that allows embedders to inject an arbitrary CldDataHarness
+// into the runtime by definining a subclass of CldDataHarnessFactory and
+// setting the global instance of it with Set(CldDataHarnessFactory*).
+// Chromium code should use the factory instance returned by Get() to obtain
+// CldDataHarness instances.
+class CldDataHarnessFactory {
+ public:
+  CldDataHarnessFactory() {}
+  virtual ~CldDataHarnessFactory() {}
+
+  // Create a new CldDataHarness.
+  // The default implementation returns a simple CldDataHarness, which is
+  // likely to be incorrect for most non-static CLD use cases.
+  virtual scoped_ptr<CldDataHarness> CreateCldDataHarness();

[Takashi Toyoshima, 2014/11/06 14:34:29]

I feel Create() is enough good name for this since it's trivial to create
CldDataHarness here.

[Andrew Hayden (chromium.org), 2014/11/10 14:06:35]

Please see my comments in browser_cld_data_provider_factory.h; basically, it
looks like the established pattern - if there is one - is that FooFactory.h
declares CreateFoo(), so I'm sticking with that.

[Takashi Toyoshima, 2014/11/11 07:16:36]

I see.

+
+  // Sets the CldDataHarnessFactory instance for the process.
+  static void Set(CldDataHarnessFactory* instance);
+
+  // Returns the CldDataHarnessFactory instance previously set for the process.
+  static CldDataHarnessFactory* Get();
+
+  // Fetch the global instance of the "static" factory that produces a harness
+  // suitable for use with the "static" CLD data source.
+  static CldDataHarnessFactory* GetStaticDataHarnessFactory();
+
+  // Fetch the global instance of the "standalone" factory that produces a
+  // harness suitable for use with the "standalone" CLD data source.
+  static CldDataHarnessFactory* GetStandaloneDataHarnessFactory();
+
+  // Fetch the global instance of the "component" factory that produces a
+  // harness suitable for use with the "component" CLD data source.
+  static CldDataHarnessFactory* GetComponentDataHarnessFactory();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CldDataHarnessFactory);
+};
+}  // namespace test
+
+#endif  // CHROME_BROWSER_TRANSLATE_CLD_DATA_HARNESS_FACTORY_H_