Change event routers from singletons to being owned by the ExtensionService.

chrome/browser/extensions/extension_accessibility_api.h

Index: chrome/browser/extensions/extension_accessibility_api.h
diff --git a/chrome/browser/extensions/extension_accessibility_api.h b/chrome/browser/extensions/extension_accessibility_api.h
index 2dfc4c1bf4022cdd126936e5dcfe15c3f4e25e70..93eac1ff502e1133aa8e5b562eb5606f4cd54d50 100644
--- a/chrome/browser/extensions/extension_accessibility_api.h
+++ b/chrome/browser/extensions/extension_accessibility_api.h
@@ -10,7 +10,6 @@
 #include <vector>
 
 #include "base/callback_old.h"
-#include "base/memory/singleton.h"
 #include "base/values.h"
 #include "chrome/browser/accessibility_events.h"
 #include "chrome/browser/extensions/extension_function.h"
@@ -21,11 +20,10 @@
 // to the extension system.
 class ExtensionAccessibilityEventRouter : public NotificationObserver {
  public:
-  // Single instance of the event router.
-  static ExtensionAccessibilityEventRouter* GetInstance();
+  explicit ExtensionAccessibilityEventRouter();
+  virtual ~ExtensionAccessibilityEventRouter();
 
-  // Safe to call multiple times.
-  void ObserveProfile(Profile* profile);
+  void Init();
 
   // Get the dict representing the last control that received an
   // OnControlFocus event.
@@ -45,11 +43,6 @@ class ExtensionAccessibilityEventRouter : public NotificationObserver {
   void AddOnDisabledListener(Callback* callback);
 
  private:
-  friend struct DefaultSingletonTraits<ExtensionAccessibilityEventRouter>;
-
-  ExtensionAccessibilityEventRouter();
-  virtual ~ExtensionAccessibilityEventRouter();
-
   // NotificationObserver::Observe.
   virtual void Observe(NotificationType type,
                        const NotificationSource& source,