Convert //ppapi to use std::unique_ptr

ppapi/proxy/ppb_message_loop_proxy.h

Index: ppapi/proxy/ppb_message_loop_proxy.h
diff --git a/ppapi/proxy/ppb_message_loop_proxy.h b/ppapi/proxy/ppb_message_loop_proxy.h
index e8213a9820f57ec270777b9dde84c1ee798c2309..1613959415148a80f93a828b7cf490b3b952c814 100644
--- a/ppapi/proxy/ppb_message_loop_proxy.h
+++ b/ppapi/proxy/ppb_message_loop_proxy.h
@@ -7,10 +7,11 @@
 
 #include <stdint.h>
 
+#include <memory>
+
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "ppapi/proxy/interface_proxy.h"
@@ -84,7 +85,7 @@ class PPAPI_PROXY_EXPORT MessageLoopResource : public MessageLoopShared {
   // that it's created on the thread it will run on. NULL for the main thread
   // loop, since that's owned by somebody else. This is needed for Run and Quit.
   // Any time we post tasks, we should post them using task_runner_.
-  scoped_ptr<base::MessageLoop> loop_;
+  std::unique_ptr<base::MessageLoop> loop_;
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   // Number of invocations of Run currently on the stack.