Automatically trigger installation of high-quality speech synthesis extension.

chrome/browser/extensions/external_component_loader.h

Index: chrome/browser/extensions/external_component_loader.h
diff --git a/chrome/browser/extensions/external_component_loader.h b/chrome/browser/extensions/external_component_loader.h
index 1bc75a04fc69faf2d89f180ab6b87adfe28accda..b27d50485bb6a3e8c44de31fb9c795f3d70313e2 100644
--- a/chrome/browser/extensions/external_component_loader.h
+++ b/chrome/browser/extensions/external_component_loader.h
@@ -8,7 +8,12 @@
 #include <string>
 
 #include "base/compiler_specific.h"
+#include "base/containers/hash_tables.h"
+#include "base/memory/weak_ptr.h"
 #include "chrome/browser/extensions/external_loader.h"
+#include "chrome/browser/profiles/profile.h"
+
+class PrefChangeRegistrar;
 
 namespace extensions {
 
@@ -18,12 +23,17 @@ namespace extensions {
 // and don't get access to component only APIs.
 // Instances of this class are expected to be created and destroyed on the UI
 // thread and they are expecting public method calls from the UI thread.
-class ExternalComponentLoader : public ExternalLoader {
+class ExternalComponentLoader
+    : public ExternalLoader,
+      public base::SupportsWeakPtr<ExternalComponentLoader> {
  public:
-  ExternalComponentLoader();
+  explicit ExternalComponentLoader(Profile* profile);
 
   static bool IsEnhancedBookmarksExperimentEnabled();
 
+  // Register speech synthesis prefs for a profile.
+  static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
+
  protected:
   virtual void StartLoading() OVERRIDE;
 
@@ -31,6 +41,20 @@ class ExternalComponentLoader : public ExternalLoader {
   friend class base::RefCountedThreadSafe<ExternalLoader>;
   virtual ~ExternalComponentLoader();
 
+  // The profile that this loader is associated with. It listens for
+  // preference changes for that profile.
+  Profile* profile_;
+
+#if defined(OS_CHROMEOS)
+  // The pref change registrar, so we can watch for pref changes.
+  scoped_ptr<PrefChangeRegistrar> pref_change_registrar_;
+
+  // A map from language code to the extension id of the high-quality
+  // extension for that language in the web store, if any - for loading
+  // speech synthesis component extensions.
+  base::hash_map<std::string, std::string> lang_to_extension_id_map_;
+#endif
+
   DISALLOW_COPY_AND_ASSIGN(ExternalComponentLoader);
 };