Fixes for re-enabling more MSVC level 4 warnings: ppapi/ edition

ppapi/cpp/dev/buffer_dev.cc

 // Copyright (c) 2011 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 "ppapi/cpp/dev/buffer_dev.h"
 
 #include "ppapi/c/dev/ppb_buffer_dev.h"
 #include "ppapi/cpp/instance_handle.h"
 #include "ppapi/cpp/module.h"
 #include "ppapi/cpp/module_impl.h"
@@ skipping 41 matching lines @@
   get_interface<PPB_Buffer_Dev>()->Unmap(pp_resource());
 }
 
 Buffer_Dev& Buffer_Dev::operator=(const Buffer_Dev& rhs) {
   Resource::operator=(rhs);
   Init();
   return *this;
 }
 
 void Buffer_Dev::Init() {
-  if (!get_interface<PPB_Buffer_Dev>()->Describe(pp_resource(), &size_) ||
-      !(data_ = get_interface<PPB_Buffer_Dev>()->Map(pp_resource()))) {
-    data_ = NULL;
-    size_ = 0;
+  if (get_interface<PPB_Buffer_Dev>()->Describe(pp_resource(), &size_)) {
+    data_ = get_interface<PPB_Buffer_Dev>()->Map(pp_resource());
+    if (data_)
+      return;
   }
+  data_ = NULL;
+  size_ = 0;
 }
 
 }  // namespace pp