Remove one thread hop while fetching matching rules

chrome/browser/android/data_usage/external_data_use_observer_bridge.cc

Index: chrome/browser/android/data_usage/external_data_use_observer_bridge.cc
diff --git a/chrome/browser/android/data_usage/external_data_use_observer_bridge.cc b/chrome/browser/android/data_usage/external_data_use_observer_bridge.cc
index 63e49661b8afda4599d288df6109992e2e8f4885..9ef7a35af7cb67921102eaccf1b1979d6b2c2e5d 100644
--- a/chrome/browser/android/data_usage/external_data_use_observer_bridge.cc
+++ b/chrome/browser/android/data_usage/external_data_use_observer_bridge.cc
@@ -172,7 +172,19 @@ void ExternalDataUseObserverBridge::OnControlAppInstallStateChange(
     jobject obj,
     bool is_control_app_installed) const {
   DCHECK(thread_checker_.CalledOnValidThread());
-  data_use_tab_model_->OnControlAppInstallStateChange(is_control_app_installed);
+  if (data_use_tab_model_) {
+    data_use_tab_model_->OnControlAppInstallStateChange(
+        is_control_app_installed);
+  }
+}
+
+void ExternalDataUseObserverBridge::ShouldRegisterAsDataUseObserver(
+    bool should_register) const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  io_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&ExternalDataUseObserver::ShouldRegisterAsDataUseObserver,
+                 external_data_use_observer_, should_register));
 }
 
 bool RegisterExternalDataUseObserver(JNIEnv* env) {