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

components/translate/content/renderer/renderer_cld_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 COMPONENTS_TRANSLATE_CONTENT_RENDERER_RENDERER_CLD_UTILS_H_
+#define COMPONENTS_TRANSLATE_CONTENT_RENDERER_RENDERER_CLD_UTILS_H_
+
+#include "base/macros.h"
+
+namespace translate {
+
+// Renderer-side utilities for dealing with CLD data source configuration.
+// This class exists primarily to avoid duplicating code in high-level targets
+// such as the Chrome browser, Chrome shell, and so on.
+class RendererCldUtils {
+ public:
+  // Perform conditional configuration of the CLD data provider.
+  // If no specific RendererCldDataProvider has yet been set, an instance is
+  // created and assigned as appropriate for each platform. If a specific
+  // RendererCldDataProviderFactory *has* been set, this method does nothing
+  // (as a side effect of setting the default factory, subsequent invocations
+  // do nothing - making this method reentrant).
+  //
+  // This method will not overwrite a data provider configured by an embedder.
+  //
+  // Maintainers: This is the default data source. It is appropriate to
+  // ifdef this code and customize the default per-platform. This method must
+  // be invoked prior to registering components with the component updater if
+  // the component updater implementation is to be used; it is best to ensure
+  // that this method is called as early as possible.
+  static void ConfigureDefaultDataProvider();
+
+ private:
+  RendererCldUtils() {}
+  ~RendererCldUtils() {}
+  DISALLOW_COPY_AND_ASSIGN(RendererCldUtils);
+};
+
+}  // namespace translate
+
+#endif  // COMPONENTS_TRANSLATE_CONTENT_RENDERER_RENDERER_CLD_UTILS_H_