Separate memory purger from safe browsing.

chrome/browser/safe_browsing/safe_browsing_service.h

Index: chrome/browser/safe_browsing/safe_browsing_service.h
diff --git a/chrome/browser/safe_browsing/safe_browsing_service.h b/chrome/browser/safe_browsing/safe_browsing_service.h
index 65b7ea2da13d3e3de58b0f13b0cd66c811f2eca6..5571f540e00cb7340907961c7a2e00a874c1400c 100644
--- a/chrome/browser/safe_browsing/safe_browsing_service.h
+++ b/chrome/browser/safe_browsing/safe_browsing_service.h
@@ -21,6 +21,8 @@
 #include "base/task.h"
 #include "base/time.h"
 #include "chrome/browser/safe_browsing/safe_browsing_util.h"
+#include "content/common/notification_observer.h"
+#include "content/common/notification_registrar.h"
 #include "googleurl/src/gurl.h"
 
 class MalwareDetails;
@@ -39,7 +41,8 @@ class URLRequestContextGetter;
 
 // Construction needs to happen on the main thread.
 class SafeBrowsingService
-    : public base::RefCountedThreadSafe<SafeBrowsingService> {
+    : public base::RefCountedThreadSafe<SafeBrowsingService>,
+      public NotificationObserver {
  public:
   class Client;
   // Users of this service implement this interface to be notified
@@ -410,6 +413,11 @@ class SafeBrowsingService
   // Adds the given entry to the whitelist.  Called on the UI thread.
   void UpdateWhitelist(const UnsafeResource& resource);
 
+  // NotificationObserver override
+  virtual void Observe(NotificationType type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details) OVERRIDE;
+
   // The factory used to instanciate a SafeBrowsingService object.
   // Useful for tests, so they can provide their own implementation of
   // SafeBrowsingService.
@@ -472,6 +480,8 @@ class SafeBrowsingService
   // Similar to |download_urlcheck_timeout_ms_|, but for download hash checks.
   int64 download_hashcheck_timeout_ms_;
 
+  NotificationRegistrar registrar_;
+
   DISALLOW_COPY_AND_ASSIGN(SafeBrowsingService);
 };