Fix presubmit.

src/x64/lithium-x64.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1379 matching lines @@
 
   virtual void PrintDataTo(StringStream* stream);
 
   Handle<JSFunction> function() { return hydrogen()->function(); }
   int arity() const { return hydrogen()->argument_count() - 1; }
 };
 
 
 class LInvokeFunction: public LTemplateInstruction<1, 1, 0> {
  public:
-  LInvokeFunction(LOperand* function) {
+  explicit LInvokeFunction(LOperand* function) {
     inputs_[0] = function;
   }
 
   DECLARE_CONCRETE_INSTRUCTION(InvokeFunction, "invoke-function")
   DECLARE_HYDROGEN_ACCESSOR(InvokeFunction)
 
   LOperand* function() { return inputs_[0]; }
 
   virtual void PrintDataTo(StringStream* stream);
 
@@ skipping 779 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::int
 
 #endif  // V8_X64_LITHIUM_X64_H_