chrome: Cleanup class/struct forward declarations

chrome/browser/loader/safe_browsing_resource_throttle.h

Index: chrome/browser/loader/safe_browsing_resource_throttle.h
diff --git a/chrome/browser/loader/safe_browsing_resource_throttle.h b/chrome/browser/loader/safe_browsing_resource_throttle.h
index 17a93d716d2d9a6e9eb5c406d47e6223acb26dc6..c60bf4f81c126d02b21c730292f6c3de407812d5 100644
--- a/chrome/browser/loader/safe_browsing_resource_throttle.h
+++ b/chrome/browser/loader/safe_browsing_resource_throttle.h
@@ -21,16 +21,10 @@
 #include "net/log/net_log_with_source.h"
 #include "url/gurl.h"
 
-class ResourceDispatcherHost;
-
 namespace net {
 class URLRequest;
 }
 
-namespace safe_browsing {
-class V4LocalDatabaseManager;
-}
-
 // SafeBrowsingResourceThrottle checks that URLs are "safe" before
 // navigating to them. To be considered "safe", a URL must not appear in the
 // malware/phishing blacklists (see SafeBrowsingService for details).