Renderers should obtain browser InterfaceProvider by connecting to browser

content/browser/android/interface_registry_android_impl.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/android/interface_registry_android_impl.h"
 
 #include <utility>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "base/callback.h"
 #include "base/memory/ptr_util.h"
+#include "content/public/browser/browser_thread.h"
 #include "jni/InterfaceRegistry_jni.h"
 #include "mojo/public/cpp/system/message_pipe.h"
 #include "services/shell/public/cpp/interface_provider.h"
 #include "services/shell/public/cpp/interface_registry.h"
 
 using base::android::AttachCurrentThread;
 using base::android::ConvertJavaStringToUTF8;
 using base::android::ScopedJavaGlobalRef;
 
 namespace content {
@@ skipping 57 matching lines @@
 
   ScopedJavaGlobalRef<jobject> j_scoped_interface_registry;
   j_scoped_interface_registry.Reset(env, j_interface_registry);
 
   ScopedJavaGlobalRef<jobject> j_scoped_manager;
   j_scoped_manager.Reset(env, j_manager);
 
   ScopedJavaGlobalRef<jobject> j_scoped_factory;
   j_scoped_factory.Reset(env, j_factory);
 
+  // All Java services must be bound on the main thread.

[Ken Rockot(use gerrit already), 2016/07/29 17:09:45]

nit: s/services/interfaces/

+  scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner =
+      BrowserThread::GetTaskRunnerForThread(BrowserThread::UI);
   interface_registry_->AddInterface(
-      name, base::Bind(&CreateImplAndAttach, j_scoped_interface_registry,
-                        j_scoped_manager, j_scoped_factory),
-      nullptr);
+      name,
+      base::Bind(&CreateImplAndAttach, j_scoped_interface_registry,
+                 j_scoped_manager, j_scoped_factory),
+      ui_task_runner);
 }
 
 void InterfaceRegistryAndroidImpl::RemoveInterface(
     JNIEnv* env,
     const JavaParamRef<jobject>& j_interface_registry,
     const JavaParamRef<jstring>& j_name) {
   std::string name(ConvertJavaStringToUTF8(env, j_name));
   interface_registry_->RemoveInterface(name);
 }
 
 }  // namespace content