EDK: Move {platform_handle,scoped_platform_handle}.* to //mojo/edk/platform.

mojo/edk/system/message_pipe_test_utils.h

Index: mojo/edk/system/message_pipe_test_utils.h
diff --git a/mojo/edk/system/message_pipe_test_utils.h b/mojo/edk/system/message_pipe_test_utils.h
index 29bf70985fb74a7f3f9ee2e7ae6ffd434f7633d6..cbd0b70b924cefa3406dfeb560e02509b7bda0c7 100644
--- a/mojo/edk/system/message_pipe_test_utils.h
+++ b/mojo/edk/system/message_pipe_test_utils.h
@@ -6,6 +6,7 @@
 #define MOJO_EDK_SYSTEM_MESSAGE_PIPE_TEST_UTILS_H_
 
 #include "mojo/edk/embedder/simple_platform_support.h"
+#include "mojo/edk/platform/scoped_platform_handle.h"
 #include "mojo/edk/system/channel.h"
 #include "mojo/edk/system/test/test_io_thread.h"
 #include "mojo/edk/test/multiprocess_test_helper.h"
@@ -30,14 +31,14 @@ class ChannelThread {
   explicit ChannelThread(embedder::PlatformSupport* platform_support);
   ~ChannelThread();
 
-  void Start(embedder::ScopedPlatformHandle platform_handle,
+  void Start(platform::ScopedPlatformHandle platform_handle,
              util::RefPtr<ChannelEndpoint>&& channel_endpoint);
   void Stop();
 
  private:
   // TODO(vtl): |channel_endpoint| should be an rvalue reference, but that
   // doesn't currently work correctly with base::Bind.
-  void InitChannelOnIOThread(embedder::ScopedPlatformHandle platform_handle,
+  void InitChannelOnIOThread(platform::ScopedPlatformHandle platform_handle,
                              util::RefPtr<ChannelEndpoint> channel_endpoint);
   void ShutdownChannelOnIOThread();