Some scoped_ptr -> std::unique_ptr conversion, especially under //mojo.

mojo/message_pump/handle_watcher.h

Index: mojo/message_pump/handle_watcher.h
diff --git a/mojo/message_pump/handle_watcher.h b/mojo/message_pump/handle_watcher.h
index 9c18476135a811c26989a80a8e2d40cd94307c3c..88c129b0511ad1c34ddf9366465dd1f845ab5eb4 100644
--- a/mojo/message_pump/handle_watcher.h
+++ b/mojo/message_pump/handle_watcher.h
@@ -5,9 +5,10 @@
 #ifndef MOJO_MESSAGE_PUMP_HANDLE_WATCHER_H_
 #define MOJO_MESSAGE_PUMP_HANDLE_WATCHER_H_
 
+#include <memory>
+
 #include "base/callback_forward.h"
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/run_loop.h"
 #include "mojo/public/c/system/time.h"
 #include "mojo/public/cpp/system/handle.h"
@@ -52,8 +53,8 @@ class HandleWatcher {
   class SameThreadWatchingState;
   class SecondaryThreadWatchingState;
 
-  // If non-NULL Start() has been invoked.
-  scoped_ptr<StateBase> state_;
+  // If non-null, Start() has been invoked.
+  std::unique_ptr<StateBase> state_;
 
   DISALLOW_COPY_AND_ASSIGN(HandleWatcher);
 };