Update from chromium https://crrev.com/302282

tools/clang/plugins/FindBadConstructsConsumer.cpp

 // 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.
 
 #include "FindBadConstructsConsumer.h"
 
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/AST/Attr.h"
 #include "clang/Lex/Lexer.h"
 #include "llvm/Support/raw_ostream.h"
@@ skipping 346 matching lines @@
 // virtual method overrides a method from a base class, only the override
 // specifier should be used. If the method should not be overridden by derived
 // classes, only the final specifier should be used.
 void FindBadConstructsConsumer::CheckVirtualSpecifiers(
     const CXXMethodDecl* method) {
   bool is_override = method->size_overridden_methods() > 0;
   bool has_virtual = method->isVirtualAsWritten();
   OverrideAttr* override_attr = method->getAttr<OverrideAttr>();
   FinalAttr* final_attr = method->getAttr<FinalAttr>();
 
-  if (method->isPure())
+  if (method->isPure() && !options_.strict_virtual_specifiers)
     return;
 
   if (IsMethodInBannedOrTestingNamespace(method))
     return;
 
   if (isa<CXXDestructorDecl>(method) && !options_.strict_virtual_specifiers)
     return;
 
   SourceManager& manager = instance().getSourceManager();
 
@@ skipping 365 matching lines @@
               record->getTypeForDecl()->getAsCXXRecordDecl()) {
             weak_ptr_factory_location = iter->getLocation();
           }
         }
       }
     }
   }
 }
 
 }  // namespace chrome_checker