Update platform handle (private) API "documentation"/comments.

mojo/public/platform/native/platform_handle_private_thunks.c

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mojo/public/platform/native/platform_handle_private_thunks.h"
 
 #include "mojo/public/platform/native/thunk_export.h"
 
 #include <assert.h>
 
 static struct MojoPlatformHandlePrivateThunks g_thunks = {0};
 
-MojoResult MojoCreatePlatformHandleWrapper(MojoPlatformHandle platform_handle,
-                                           MojoHandle* wrapper) {
+MojoResult MojoCreatePlatformHandleWrapper(
+    MojoPlatformHandle platform_handle,
+    MojoHandle* platform_handle_wrapper_handle) {
   assert(g_thunks.CreatePlatformHandleWrapper);
-  return g_thunks.CreatePlatformHandleWrapper(platform_handle, wrapper);
+  return g_thunks.CreatePlatformHandleWrapper(platform_handle,
+                                              platform_handle_wrapper_handle);
 }
 
-MojoResult MojoExtractPlatformHandle(MojoHandle wrapper,
+MojoResult MojoExtractPlatformHandle(MojoHandle platform_handle_wrapper_handle,
                                      MojoPlatformHandle* platform_handle) {
   assert(g_thunks.ExtractPlatformHandle);
-  return g_thunks.ExtractPlatformHandle(wrapper, platform_handle);
+  return g_thunks.ExtractPlatformHandle(platform_handle_wrapper_handle,
+                                        platform_handle);
 }
 
 THUNK_EXPORT size_t MojoSetPlatformHandlePrivateThunks(
     const struct MojoPlatformHandlePrivateThunks* thunks) {
   if (thunks->size >= sizeof(g_thunks))
     g_thunks = *thunks;
   return sizeof(g_thunks);
-}
+}