Using "static_assert" in lieu of "COMPILE_ASSERT" in extensions module

extensions/common/permissions/base_set_operators.h

 // Copyright 2013 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 EXTENSIONS_COMMON_PERMISSIONS_BASE_SET_OPERATORS_H_
 #define EXTENSIONS_COMMON_PERMISSIONS_BASE_SET_OPERATORS_H_
 
 #include <iterator>
 #include <map>
 
@@ skipping 51 matching lines @@
       return it_->second.get();
     }
 
    private:
     typename Map::const_iterator it_;
   };
 
   BaseSetOperators() {
     // Ensure |T| is convertible to us, so we can safely downcast when calling
     // methods that must exist in |T|.
-    COMPILE_ASSERT((base::is_convertible<T*, BaseSetOperators<T>*>::value),
-                   U_ptr_must_implicitly_convert_to_T_ptr);
+    static_assert((base::is_convertible<T*, BaseSetOperators<T>*>::value),
+                   "U ptr must implicitly convert to T ptr");
   }
 
   BaseSetOperators(const T& set) {
     this->operator=(set);
   }
 
   ~BaseSetOperators() {}
 
   T& operator=(const T& rhs) {
     return Assign(rhs);
@@ skipping 195 matching lines @@
     map_.clear();
   }
 
  private:
   Map map_;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_COMMON_PERMISSIONS_BASE_SET_OPERATORS_H_