Corresponding change in Pepper since EnumerateDevices contract is changed.

ppapi/shared_impl/ppb_video_capture_shared.cc

Index: ppapi/shared_impl/ppb_video_capture_shared.cc
===================================================================
--- ppapi/shared_impl/ppb_video_capture_shared.cc	(revision 148913)
+++ ppapi/shared_impl/ppb_video_capture_shared.cc	(working copy)
@@ -44,6 +44,13 @@
   return InternalEnumerateDevices(devices, callback);
 }
 
+int32_t PPB_VideoCapture_Shared::StopEnumerateDevices(
+    PP_Resource* devices) {
+  devices_ = NULL;
+  enumerate_devices_callback_ = NULL;
+  return InternalStopEnumerateDevices(devices);
+}
+
 int32_t PPB_VideoCapture_Shared::Open(
     const std::string& device_id,
     const PP_VideoCaptureDeviceInfo_Dev& requested_info,
@@ -122,9 +129,7 @@
     *devices_ = PPB_DeviceRef_Shared::CreateResourceArray(
         resource_object_type_, pp_instance(), devices);
   }
-  devices_ = NULL;
-
-  TrackedCallback::ClearAndRun(&enumerate_devices_callback_, result);
+  enumerate_devices_callback_->Run(result);
 }
 
 void PPB_VideoCapture_Shared::OnOpenComplete(int32_t result) {