Fix newly discovered presubmit errors.

test/cctest/compiler/test-instruction.cc

 // Copyright 2014 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.
 
 #include "src/v8.h"
 #include "test/cctest/cctest.h"
 
 #include "src/compiler/code-generator.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/instruction.h"
 #include "src/compiler/machine-operator.h"
 #include "src/compiler/node.h"
 #include "src/compiler/operator.h"
 #include "src/compiler/schedule.h"
 #include "src/compiler/scheduler.h"
 #include "src/lithium.h"
 
 using namespace v8::internal;
 using namespace v8::internal::compiler;
 
 typedef v8::internal::compiler::Instruction TestInstr;
 typedef v8::internal::compiler::InstructionSequence TestInstrSeq;
 
 // A testing helper for the register code abstraction.
 class InstructionTester : public HandleAndZoneScope {
  public:  // We're all friends here.
-  explicit InstructionTester()
+  InstructionTester()
       : isolate(main_isolate()),
         graph(zone()),
         schedule(zone()),
         info(static_cast<HydrogenCodeStub*>(NULL), main_isolate()),
         linkage(&info),
         common(zone()),
         machine(zone(), kMachineWord32),
         code(NULL) {}
 
   ~InstructionTester() { delete code; }
@@ skipping 302 matching lines @@
           CHECK_EQ(inputs[z], m->InputAt(z));
         }
 
         for (size_t z = 0; z < k; z++) {
           CHECK_EQ(temps[z], m->TempAt(z));
         }
       }
     }
   }
 }