Remove content::BrowserThread knowledge from Device Sensors

content/browser/browser_main_loop.cc

Index: content/browser/browser_main_loop.cc
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index 325b85d3ec2686b68b642fcd1e2d759b1f156b79..9eec42ef670a6fb6bc887612b571239c52c4dff5 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -1169,7 +1169,7 @@ void BrowserMainLoop::ShutdownThreadsAndCleanUp() {
   }
   {
     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:SensorService");
-    DeviceSensorService::GetInstance()->Shutdown();
+    DeviceSensorService::GetInstance()->ShutDownOnUIThread();
   }
 #if !defined(OS_ANDROID)
   {
@@ -1352,7 +1352,13 @@ int BrowserMainLoop::BrowserThreadsStarted() {
 
   {
     TRACE_EVENT0("startup",
-      "BrowserMainLoop::BrowserThreadsStarted::SaveFileManager");
+                 "BrowserMainLoop::BrowserThreadsStarted::DeviceSensorService");
+    DeviceSensorService::GetInstance()->InitOnUIThread();
+  }
+
+  {
+    TRACE_EVENT0("startup",
+                 "BrowserMainLoop::BrowserThreadsStarted::SaveFileManager");
     save_file_manager_ = new SaveFileManager();
   }