Remove all remaining traces of MessageLoopProxy.

extensions/shell/browser/shell_device_client.cc

Index: extensions/shell/browser/shell_device_client.cc
diff --git a/extensions/shell/browser/shell_device_client.cc b/extensions/shell/browser/shell_device_client.cc
index 857e2a4f2fcff25d6a4027bc26533ddf4f3fa65e..81dabf4c72a527d5ca057d0475b07259b5546692 100644
--- a/extensions/shell/browser/shell_device_client.cc
+++ b/extensions/shell/browser/shell_device_client.cc
@@ -22,7 +22,7 @@ device::UsbService* ShellDeviceClient::GetUsbService() {
 
   if (!usb_service_) {
     usb_service_ = device::UsbService::Create(
-        BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE));
+        BrowserThread::GetTaskRunnerForThread(BrowserThread::FILE));
   }
   return usb_service_.get();
 }
@@ -31,7 +31,7 @@ device::HidService* ShellDeviceClient::GetHidService() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   if (!hid_service_) {
     hid_service_ = device::HidService::Create(
-        BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE));
+        BrowserThread::GetTaskRunnerForThread(BrowserThread::FILE));
   }
   return hid_service_.get();
 }