Add "enabled" state to the ClientSideDetectionService.

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 6dbcdc0b638e804e6636fd2c4e601c155bb73ca8..a6191230fb79854050e80939a54999187aaef86f 100644
--- a/chrome/browser/safe_browsing/safe_browsing_service.h
+++ b/chrome/browser/safe_browsing/safe_browsing_service.h
@@ -42,6 +42,10 @@ namespace net {
 class URLRequestContextGetter;
 }
 
+namespace safe_browsing {
+class ClientSideDetectionService;
+}
+
 // Construction needs to happen on the main thread.
 class SafeBrowsingService
     : public base::RefCountedThreadSafe<SafeBrowsingService>,
@@ -522,6 +526,11 @@ class SafeBrowsingService
   // Used to track creation and destruction of profiles on the UI thread.
   NotificationRegistrar prefs_registrar_;
 
+  // The ClientSideDetectionService depends on the same preference as the
+  // SafeBrowsingService. So the SafeBrowsingService updates the state of
+  // the ClientSideDetectionService when its own state changes.
+  safe_browsing::ClientSideDetectionService* csd_service_;
+
   DISALLOW_COPY_AND_ASSIGN(SafeBrowsingService);
 };