Mojo: Change how we handle invalid pointer arguments (at the system layer).

mojo/system/mapping_table.h

 // Copyright 2014 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.
 
 #ifndef MOJO_SYSTEM_MAPPING_TABLE_H_
 #define MOJO_SYSTEM_MAPPING_TABLE_H_
 
 #include <stdint.h>
 
 #include <vector>
@@ skipping 21 matching lines @@
 //
 // This class is NOT thread-safe; locking is left to |Core|.
 class MOJO_SYSTEM_IMPL_EXPORT MappingTable {
  public:
   MappingTable();
   ~MappingTable();
 
   // Tries to add a mapping. (Takes ownership of the mapping in all cases; on
   // failure, it will be destroyed.)
   MojoResult AddMapping(scoped_ptr<RawSharedBufferMapping> mapping);
-  MojoResult RemoveMapping(void* address);
+  MojoResult RemoveMapping(uintptr_t address);
 
  private:
   friend bool internal::ShutdownCheckNoLeaks(Core*);
 
   typedef base::hash_map<uintptr_t, RawSharedBufferMapping*>
       AddressToMappingMap;
   AddressToMappingMap address_to_mapping_map_;
 
   DISALLOW_COPY_AND_ASSIGN(MappingTable);
 };
 
 }  // namespace system
 }  // namespace mojo
 
 #endif  // MOJO_SYSTEM_MAPPING_TABLE_H_