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

components/translate/content/renderer/renderer_cld_data_provider.h

Index: components/translate/content/renderer/renderer_cld_data_provider.h
diff --git a/components/translate/content/renderer/renderer_cld_data_provider.h b/components/translate/content/renderer/renderer_cld_data_provider.h
index 4da053a8a7e98e4e4d7f15c8241325673551c7bd..367da49f740a79b4e1aa9ce45b9275a1aaf9defd 100644
--- a/components/translate/content/renderer/renderer_cld_data_provider.h
+++ b/components/translate/content/renderer/renderer_cld_data_provider.h
@@ -12,10 +12,6 @@ namespace IPC {
 class Message;
 }
 
-namespace content {
-class RenderViewObserver;
-}
-
 namespace translate {
 
 // Renderer-side interface responsible for providing CLD data.
@@ -29,6 +25,7 @@ namespace translate {
 // constant from ipc_message_start.h
 class RendererCldDataProvider : public IPC::Listener {
  public:
+  RendererCldDataProvider();
   virtual ~RendererCldDataProvider() {}
 
   // (Inherited from IPC::Listener)
@@ -39,33 +36,44 @@ class RendererCldDataProvider : public IPC::Listener {
   // loop thread.
   // This method is defined as virtual in order to force the implementation to
   // define the specific IPC message(s) that it handles.
-  virtual bool OnMessageReceived(const IPC::Message&) = 0;
+  virtual bool OnMessageReceived(const IPC::Message&) OVERRIDE;
 
   // Invoked by the renderer process to request that CLD data be obtained and
   // that CLD be initialized with it. The implementation is expected to
   // communicate with the paired BrowserCldDataProvider implementation on the
   // browser side.
   // This method must be invoked on the message loop thread.
-  virtual void SendCldDataRequest() = 0;
+  virtual void SendCldDataRequest();

[Andrew Hayden (chromium.org), 2014/09/26 10:22:49]

Document the default behavior of all the functions that are no longer
pure-virtual.

[Andrew Hayden (chromium.org), 2014/10/28 15:18:39]

Done.

 
   // Convenience method that tracks whether or not CLD data is available.
   // This method can be used in the absence of a callback (i.e., if the caller
   // wants a simple way to check the state of CLD data availability without
   // keeping a separate boolean flag tripped by a callback).
-  virtual bool IsCldDataAvailable() = 0;
+  virtual bool IsCldDataAvailable();
 
   // Sets a callback that will be invoked when CLD data is successfully
   // obtained from the paired BrowserCldDataProvider implementation on the
   // browser side, after CLD has been successfully initialized.
   // Both the initialization of CLD2 as well as the invocation of the callback
   // must happen on the message loop thread.
-  virtual void SetCldAvailableCallback(base::Callback<void(void)>) = 0;
-};
+  virtual void SetCldAvailableCallback(base::Callback<void(void)>);
 
-// Static factory function defined by the implementation that produces a new
-// provider for the specified render view host.
-RendererCldDataProvider* CreateRendererCldDataProviderFor(
-    content::RenderViewObserver*);
+  // Sets the instance of the provider used by this process, optionally
+  // overwriting the previous value. Embedders and narrow use-cases (such as
+  // shells and test code) should use the overwrite capability, while generic
+  // code should not.
+  // If another instance is already set, it is immediately destroyed prior to
+  // updating the global pointer to point to the specified instance.
+  static void Set(RendererCldDataProvider* instance, bool overwrite);
+
+  // Returns true if and only if the current instance for this process is not
+  // NULL.
+  static bool IsInitialized();
+
+  // Returns the instance of the provider previously set by Set(...).
+  // If no instance has been set, a default no-op provider will be returned.
+  static RendererCldDataProvider* Get();
+};
 
 }  // namespace translate