Clear GCM data when the user clears cookies and other site data

components/gcm_driver/gcm_driver_android.cc

Index: components/gcm_driver/gcm_driver_android.cc
diff --git a/components/gcm_driver/gcm_driver_android.cc b/components/gcm_driver/gcm_driver_android.cc
index d855363b5ad127a904f4b311ec1f559cb23f80b6..69da4c5e69dd449d3703b09002cc691afa11e96d 100644
--- a/components/gcm_driver/gcm_driver_android.cc
+++ b/components/gcm_driver/gcm_driver_android.cc
@@ -95,6 +95,9 @@ bool GCMDriverAndroid::RegisterBindings(JNIEnv* env) {
 void GCMDriverAndroid::OnSignedIn() {
 }
 
+void GCMDriverAndroid::OnSignedOut() {
+}
+
 void GCMDriverAndroid::Purge() {
 }