[Device Sensors] Move Mojo communication to UI thread on Android

content/browser/renderer_host/render_process_host_impl.cc

 // Copyright 2012 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.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 1261 matching lines @@
 
   scoped_refptr<base::SingleThreadTaskRunner> file_task_runner =
       BrowserThread::GetTaskRunnerForThread(BrowserThread::FILE);
   registry->AddInterface(base::Bind(&MimeRegistryImpl::Create),
                          file_task_runner);
 #if defined(USE_MINIKIN_HYPHENATION)
   registry->AddInterface(base::Bind(&hyphenation::HyphenationImpl::Create),
                          file_task_runner);
 #endif
 
-  // These callbacks will be run immediately on the IO thread.
+#if defined(OS_ANDROID)
+  // On Android the device sensors implementations need to run on the UI thread
+  // to communicate to Java.
+  AddUIThreadInterface(registry.get(), base::Bind(&DeviceLightHost::Create));
+  AddUIThreadInterface(registry.get(), base::Bind(&DeviceMotionHost::Create));
+  AddUIThreadInterface(registry.get(),
+                       base::Bind(&DeviceOrientationHost::Create));
+  AddUIThreadInterface(registry.get(),
+                       base::Bind(&DeviceOrientationAbsoluteHost::Create));
+#else
+  // On platforms other than Android the device sensors implementations run on
+  // the IO thread.
   registry->AddInterface(base::Bind(&DeviceLightHost::Create));
   registry->AddInterface(base::Bind(&DeviceMotionHost::Create));
   registry->AddInterface(base::Bind(&DeviceOrientationHost::Create));
   registry->AddInterface(base::Bind(&DeviceOrientationAbsoluteHost::Create));
+#endif  // defined(OS_ANDROID)
+
   registry->AddInterface(
       base::Bind(&URLLoaderFactoryImpl::Create, resource_message_filter_));
 
   registry->AddInterface(
       base::Bind(&VideoCaptureHost::Create,
                  BrowserMainLoop::GetInstance()->media_stream_manager()));
 
   // This is to support usage of WebSockets in cases in which there is no
   // associated RenderFrame (e.g., Shared Workers).
   AddUIThreadInterface(
@@ skipping 1708 matching lines @@
   bad_message::ReceivedBadMessage(render_process_id,
                                   bad_message::RPH_MOJO_PROCESS_ERROR);
 }
 
 void RenderProcessHostImpl::CreateURLLoaderFactory(
     mojo::InterfaceRequest<mojom::URLLoaderFactory> request) {
   URLLoaderFactoryImpl::Create(resource_message_filter_, std::move(request));
 }
 
 }  // namespace content