Add a check to the FindBadConstructs.cpp clang plugin for bad enum last values.

tools/clang/plugins/ChromeClassTester.h

 // Copyright (c) 2012 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 TOOLS_CLANG_PLUGINS_CHROMECLASSTESTER_H_
 #define TOOLS_CLANG_PLUGINS_CHROMECLASSTESTER_H_
 
 #include <set>
 #include <vector>
 
@@ skipping 37 matching lines @@
  private:
   void BuildBannedLists();
 
   void CheckTag(clang::TagDecl*);
 
   // Filtered versions of tags that are only called with things defined in
   // chrome header files.
   virtual void CheckChromeClass(clang::SourceLocation record_location,
                                 clang::CXXRecordDecl* record) = 0;
 
+  // Filtered versions of enum type that are only called with things defined
+  // in chrome header files.
+  virtual void CheckChromeEnum(clang::SourceLocation enum_location,
+                               clang::EnumDecl* enum_decl) {
+  }
+
   // Utility methods used for filtering out non-chrome classes (and ones we
   // deliberately ignore) in HandleTagDeclDefinition().
   std::string GetNamespaceImpl(const clang::DeclContext* context,
                                const std::string& candidate);
   bool InBannedDirectory(clang::SourceLocation loc);
   bool IsIgnoredType(const std::string& base_name);
 
   // Attempts to determine the filename for the given SourceLocation.
   // Returns false if the filename could not be determined.
   bool GetFilename(clang::SourceLocation loc, std::string* filename);
@@ skipping 11 matching lines @@
   std::set<std::string> ignored_record_names_;
 
   // List of decls to check once the current top-level decl is parsed.
   std::vector<clang::TagDecl*> pending_class_decls_;
 
   // TODO(tfarina): Remove once url/ directory compiles without warnings.
   bool check_url_directory_;
 };
 
 #endif  // TOOLS_CLANG_PLUGINS_CHROMECLASSTESTER_H_