Fix newly discovered presubmit errors.

src/arm64/lithium-arm64.h

 // Copyright 2013 the V8 project 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 V8_ARM64_LITHIUM_ARM64_H_
 #define V8_ARM64_LITHIUM_ARM64_H_
 
 #include "src/hydrogen.h"
 #include "src/lithium.h"
 #include "src/lithium-allocator.h"
@@ skipping 434 matching lines @@
 
   DECLARE_CONCRETE_INSTRUCTION(Drop, "drop")
 
  private:
   int count_;
 };
 
 
 class LDummy V8_FINAL : public LTemplateInstruction<1, 0, 0> {
  public:
-  explicit LDummy() { }
+  LDummy() {}
   DECLARE_CONCRETE_INSTRUCTION(Dummy, "dummy")
 };
 
 
 class LDummyUse V8_FINAL : public LTemplateInstruction<1, 1, 0> {
  public:
   explicit LDummyUse(LOperand* value) {
     inputs_[0] = value;
   }
   DECLARE_CONCRETE_INSTRUCTION(DummyUse, "dummy-use")
@@ skipping 470 matching lines @@
   LOperand* value() { return inputs_[0]; }
   LOperand* temp() { return temps_[0]; }
 
   DECLARE_CONCRETE_INSTRUCTION(CheckInstanceType, "check-instance-type")
   DECLARE_HYDROGEN_ACCESSOR(CheckInstanceType)
 };
 
 
 class LCheckMaps V8_FINAL : public LTemplateInstruction<0, 1, 1> {
  public:
-  LCheckMaps(LOperand* value = NULL, LOperand* temp = NULL) {
+  explicit LCheckMaps(LOperand* value = NULL, LOperand* temp = NULL) {
     inputs_[0] = value;
     temps_[0] = temp;
   }
 
   LOperand* value() { return inputs_[0]; }
   LOperand* temp() { return temps_[0]; }
 
   DECLARE_CONCRETE_INSTRUCTION(CheckMaps, "check-maps")
   DECLARE_HYDROGEN_ACCESSOR(CheckMaps)
 };
@@ skipping 2305 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM64_LITHIUM_ARM64_H_